由于感情生活受挫，Addison（Kate Walsh 饰）决定移居加州，加盟好友Naomi（Merrin Dungey 饰）的私人诊所，开始新的生活。面对新的环境，Addison不仅要适应加州多雨的天气，还要努力融入新的圈子。在这个私人诊所里，每个人都是医学界的高手，却都有自己难以治愈的心灵伤口。
刚刚离异的Naomi和Sam；由于妻子的逝世而陷入自责的Pete；对已婚前男友念念不忘的Violet；暗恋Violet而不敢开口的Coope。在忙碌而紧张的日常工作中，每个人都努力的追求着自己想要的幸福，试着释怀，试着重新开始。

本剧刚刚获得第64届美国金球奖最佳剧情类电视剧大奖。
15小时15分钟，手术室内外科医生让时间飞逝。然而在手术室外，时间把我们玩弄于股掌之间，甚至对最强的人来说 似乎都被时间捉弄，慢下来，徘回着，直至凝固。我们便停留在某一刻 无法向四周移动。
经历了第二季finale中的诸多变故后，每个人都在思考，都在回忆，都在考虑下一步怎么走。macdreamy意识到当初做了个错误的决定，但现在轮到 Meridith做令人伤脑筋的选择了，George还是没能用那三个字回应Kalie的炽烈的爱，Izzie也振作起来，只是不知她还能不能回来， Christina发觉自己是多么深爱Burk，每个人都有新的境遇。最后，第二季结尾悬念的主角——Meridith的内裤原来被Addison给捡到了。。。
欢迎来到Grace医院,west of Harvard最艰苦的外科住院医实习程序,医务新人最残酷的训练场.Meredith, Izzie 和 Christina,昨天还是学生,今天已是大夫.如果他们能挺过Grace医院的7年炼狱考验,她们就能成为合格的外科医生.然而摆在这三人组面前的, 不仅是艰苦的实习培训,她们还要应对善妒的男友和病态的父母,一夜激情和住房危机.面对重重难关,她们只有互相依靠.

荣获金球奖最佳戏剧类电视剧集！
荣获艾美奖最佳戏剧类影集选角！
萤幕演员公会最佳戏剧类电视剧集！
故事延续第三季精采的剧情。西雅图恩典医院因为这些实习医生之间的爱恨情仇，变得更加热闹更有可看性！
第三季中格蕾终於摆脱了德瑞克和兽医间的三角恋情，依自己的心意选择了所爱的人。伊兹在丹尼死后一厥不振，甚至想要放弃成为外科医生的梦想。克莉丝汀知道了柏克的秘密后，一直企图帮他掩饰。而乔治和性感火辣的住院医师之间的关係变得更迷离。而艾立克斯竟发现自己还是爱著伊兹！另外，马克为了艾蒂森竟也来到了西雅图恩典医院工作。
Meredith和Cristina蜜月归来（买好的机票不好浪费~），Burke已经消失无踪。去年的实习医生Meredith, Cristina, Izzie和Alex，已经获得了正式驻院医生的资格，并且有了自己的跟班，一群初出茅庐，青涩而稚嫩的实习医生。当中，有去年考试不及格的George，还有Meredith素未谋面的妹妹Lexie Grey。今天，他们将要处理一宗三车连环相撞的交通意外，大量的伤者让新来的实习手足无措，目瞪口呆。另一边厢，Derek和Meredith的感情陷入僵局，有可能他们都会和新来的同事有新的感情发展。Bailey对于Callie成为驻院总医生感到气愤，也许她一时三刻还难以接受自己现在要向Callie汇报工作。Richard留任外科主任，仍然是大家的老大~(简介转自YDY)
After failing his exam, George reluctantly faces his first day reliving his internship among a sea of fresh faces. Meanwhile, Cristina, Meredith, Izzie and Alex are in charge of their own interns and George is assigned to Meredith.
Neither Cristina or Meredith have heard from her exes since the wedding, and they don't seem overly concerned, which astounds Izzie, who is counting every day since she last spoke to George. George asks to talk to Meredith but before he can get her alone, the rest of the new interns show up in the hall and are shooed off by the residents. George gives up and joins the interns. Cristina nicknames him "Bambi," saying he needs to learn how to deal with his new situation.

Recipient of the 2007 Golden Globe Award for Best Drama Television Series and multiple Emmy nominations, including Outstanding Drama Series for the past two years, "Grey's Anatomy" returns to the ABC Television Network for its fifth season.
Is "happily ever after" possible for Meredith Grey and Derek "McDreamy" Shepherd? With Meredith experiencing a breakthrough in therapy - the realization that she and Derek can be extraordinary together, rather than ordinary apart -- she and Derek now face the highs and lows of being a committed couple.
Continuing their first year as residents at Seattle Grace Hospital, Meredith, Cristina Yang, Izzie Stevens and Alex Karev have interns of their own to mentor, including Meredith's half-sister, Lexie Grey. Lexie has become a roommate and confidante to George O'Malley, who, after divorce with Callie, a breakup with Izzie, and learning that he failed his residency test by only one point, is striving to get both his professional and personal life back on track.
After attending to his girlfriend Rebecca's mental illness on his own, and revealing that he had gone through this with his own mother, Alex finds solace in Izzie's arms. Alex must continue through this difficult time, whether or not Izzie remains by his side.
Cristina, having finally won out over her tough-as-nails mentor, Erica, is back on track as a surgeon - but is there a chance for new love in her life as well?
With the encouragement of Mark "McSteamy" Sloan, Dr. Callie Torres has taken a chance on love with cardiothoracic surgeon, Erica Hahn; now, she and Erica must figure out what happens after the first kiss.
Overseeing the residents is the no-nonsense Chief Resident, Miranda Bailey. Facing marital troubles and the difficulty of balancing her work and personal life, Bailey has handed her responsibilities as head of the free clinic over to Izzie. Also striving for balance is Chief of Surgery, Richard Webber, who has reunited with his estranged wife, Adele.
The doctors of Seattle Grace Hospital deal with life-or-death consequences on a daily basis - it's in one another that they find comfort, friendship and love. Together they're discovering that neither medicine nor relationships can be defined in black and white. Real life only comes in shades of grey.
"Grey's Anatomy" stars Ellen Pompeo as Meredith Grey, Patrick Dempsey as Derek Shepherd, Sandra Oh as Cristina Yang, Katherine Heigl as Isobel "Izzie" Stevens, Justin Chambers as Alex Karev, T.R. Knight as George O'Malley, Chandra Wilson as Miranda Bailey, James Pickens, Jr. as Richard Webber, Sara Ramirez as Callie Torres, Eric Dane as Mark Sloan, Chyler Leigh as Lexie Grey, and Brooke Smith as Erica Hahn.

西雅图格雷斯医院迎来新一批实习生，梅雷迪斯·格雷（艾伦·旁派 Ellen Pompeo 饰）、克里斯蒂娜·杨（吴珊卓 Sandra Oh 饰）、伊泽贝尔·斯蒂文（凯瑟琳·海格尔 Katherine Heigl 饰）、乔治·梅利（T·R·奈特 T.R. Knight 饰） 、亚里克斯·卡莱（贾斯汀·钱伯斯 Justin Chambers 饰），五个医学院好友同期毕业，需要以良好表现争夺住院医师正式席位。进入医院伊始，梅雷迪斯崩溃地发现前晚在酒吧和她发生一夜情的男人，竟然是神经外科医生德立克·舍伯（帕特里克·德姆西 Patrick Dempsey 饰），两人纠葛就此开始；克里斯蒂娜吸引了胸外科医师普雷斯顿·伯克的注意，因为他们同样高傲和野心勃勃；乔治悄悄爱着梅雷迪斯；美丽的伊泽贝尔第一时间掀起流言，一年的实习期注定充满高密度的压力竞争与荷尔蒙……

香港SARS疫潮过后，人们终于从阴霾中走出来。脑外科医生程至美（吴启华饰）突然得知前女友的死讯，情绪崩溃，极度自责抑郁。法医岑雅晴（黎姿饰）伴其左右，鼓励他重新建立信心。急症室医生黎国柱（林保怡饰）结束了与女友的恋情，却卷入与骨科医生叶淘（吴美珩饰）及见习医生曾淑淇（廖碧儿饰）的三角恋中。不幸感染SARS的心脏科医生林敏智（陈豪饰）留下后遗症，为保全名声而隐瞒病情，却令病情日益恶化。妇产科医生万安生（邵美琪饰）与急症科医生向众仁（曹永廉饰）正计划共同生活，然而却因护士戴玉莹（姚嘉妮饰）的介入而面临一场情感考验。
由香港无线电视制作的现代时装医务纪实电视剧《妙手仁心3》是《妙手仁心》系列的第三辑，监制戚其义与编剧周旭明的黄金组合更是精心打造此辑“妙手系列”。此辑剧集在风格上延续了前两辑经典之处，一如既往的得到医务人员协助实景拍摄，继续讲述医护人员在工作中的点滴故事。

Jackie（蔡少芬 饰）罹患脑癌后一直昏迷，程至美（吴启华 饰）一直守候照顾。至美的用情专一深深感动了同一所医院的医生何心研（蒙嘉慧 饰）。富家女出身的心研跟风流医生林敏智（陈豪 饰）本是恋人，遇上了至美才让她看到了细水长流的爱情。
江满月（苏永康 饰）因爱滋病逝世，姐姐新月（陈慧珊 饰）伤心欲绝，黎国柱（林宝怡 饰）在身边给予安慰，两人之间的爱情再次滋生。好景不长，国柱与助手阮朗平（陈洁仪 饰）日久生情了。朗平后来觉得对新月十分歉意，独自离开了香港。不久国柱知道朗平怀孕了，便推测自己是否孩子的父亲，情急之下把真相告诉了新月……

一群医务精英每天都救死扶伤，在忙碌的日子里常常有许多事烦扰他们。
急症室高级医生黎国柱（林保怡 饰）风流不羁，一次偶然发现肿瘤科医生满月（苏永康 饰）的姐姐是律师新月（陈慧珊 饰）。原来国柱曾经有负于她。当两人再次重逢，新月发现自己对国柱余情未了。
同样室急症室医生的裕 （马浚伟 饰）则周旋于护士长霞（陈芷菁 饰）与见习医生冬（曹众 饰）之间，无法选择，烦恼不已。
脑外科高级医生程至美（吴启华 饰）与妻子（梁婉静 饰）离婚，竟同事Jackie（蔡少芬 饰）误会至美用情不专。经过一番了解后，才清楚对方的为人，此时情愫也暗生了。怎料Jackie发现自己患上脑肿瘤……