It is when a man ejaculates with minimum sexual stimulation before or shortly after penetration.  It happens before the man wants it to.  In order to have this diagnosis, it must happen persistently in his life.

There are, however, times that premature ejaculation is expected and normal.  Some of these times are:  when a man has not had sex in a while; when he starts to have intercourse with a new person; when the sexual position, location, time, etc. is new; when there is distress in the relationship.

Premature ejaculation is the easiest male sexual problem to treat.  Treatments are successful, relatively fast, and easy to do.  Men are usually very relieved to find this out and wish they had sought treatment earlier.

A good book on the subject is P.E.: How to Overcome Premature Ejaculation by Helen Singer Kaplan, available online and at bookstores locally.  However remember that treatment books can only give a general description of the problem and its treatment and is not tailored to each individual.

Premature ejaculation is the third most frequent problem men seek to fix in sex therapy.