影片假设那些闹得儿童们辗转反侧的怪物不仅是真的，而且生活在另一度空间。他们那个世界的动力是儿童的尖叫。怪物公司跟那些高效的现代化企业一样，为员工制定了工作指标。一半像猩猩、一半像狗熊的苏利文乃怪物公司的生产冠军，可他有一次不小心把人类世界的一个小女孩带回了怪物公司。这下可闯了大祸，因为怪物世界其实最怕人，简直把他们看成天花带菌者。不过，苏利文慢慢发现女孩没有恶意，而且天真可爱，他便千方百计保护她，一方面躲避他那死对头的追杀，一方面试图把女孩送回她自己的世界。

  If I Didn't Have You - Billy Crystal / John Goodman
    如果我不曾拥有你 - Billy Crystal / John Goodman
    作词：Mitchel Musso / Emily Oosment
    作曲：Mitchel Musso / Emily Osment
    编曲：迪士尼
    If I were a rich man
    如果我曾是个富有的人
    With a million or two
    拥有一两千万
    I'd live in a penthouse
    我曾住在阁楼
    In a room with a view
    一个可以眺望风景的房间
    And if I were handsome
    如果我曾帅气
    Well it could happen
    好吧 也许一切都会实现
    Those dreams do come true
    那些梦想会实现
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin'
    我将会一无所有
    Let me tell you something
    告诉你
    For years I have envied
    这些年我一直嫉妒
    Your grace and your charm
    你的优雅 你的魅力
    Everyone loves you you know
    每个人都爱你 你知道
    Yes I know I know I know
    是的 我知道 我知道 我知道
    But I must admit it
    但是我必须承认
    Big guy you always come through
    你总会安然无恙
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    You and me together
    你和我注定要在一起
    That's how it always should be
    这是通常的结局
    One without the other
    彼此不能离开彼此
    Don't mean nothing to me nothing to me
    于我而言 毫无意义
    Ya I wouldn't be nothin'
    呀 你于我而言毫无意义
    If I didn't have you to serve
    如果我与你也毫无用处
    Just a punky little eyeball
    柔软的眼球
    And a funky optic nerve
    挑战这敏感的视觉神经
    Hey I never told you this but uh
    嘿 我从未告诉过你 啊
    Sometimes I get a little blue
    有时我会情绪低落
    But I wouldn't have nothin' if I didn't have you
    但是 如果我不曾拥有你 我将会一无所有
    Let's Dance
    让我们跳舞吧
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    Wouldn't know where to go no no
    不知该何去何从 不 不
    Wouldn't know what to do
    不知该做什么
    I don't have to say it
    我无需赘言
    Cause we both know it's true
    因为我们都知道那是事实
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    One more time
    再一次
    I don't have to say it
    我无需赘言
    Cause we both know it's true
    因为我们都知道那是事实
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    I wouldn't have nothin' if I didn't have you
    如果我不曾拥有你 我将会一无所有
    Y O U that means you
    Y O U意味着你