When followed by an infinitive, yes. See here for verb meanings when they are followed by a preposition - http://spanishplus.tripod.com/VerbsandPrepositions.htm#TopOfPage
Sorry. I looked into taco32's post, for my own education, and wondered if there were any other meanings for "dejar de + infinitive". None have come up so far. Thanks for the link confirming this, which I why I said that the "rule stands". I should have kept my clarification & confirmation to myself, I think.
Dejar has 2 meanings:
Tengo que dejar de fumar = i have to quit, stop, ''leave'' smoking.
Ella me deja fumar en su casa = she lets me smoke in her house.
The general meaning of DEJAR is ''to let go of...'' , so depending on context it can mean to let go of... to let... to leave... to quit... to stop...
Hope this helps a little bit...
Dejar means to leave or let I believe. I think this is one of multiple ways to tell someone to cease something - it doesn't really have a perfect English equivalent, but you can recognize the logic that forms the sentence although it's not English logic. If you learn the logic of sentence structures that don't make sense in English, you'll learn more about how the language internally works.
What I've found: http://translate.google.com/#es/en/dejar%20de http://answers.yahoo.com/question/index?qid=20080921135500AAmwhqI It seems that 'dejar de' is and idiomatic way of saying 'to stop'.