Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. It is usually the result of sexual stimulation, which may include prostate stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep (a nocturnal emission). Anejaculation is the condition of being unable to ejaculate.

The process of ejaculation is an intense sensation (French "la petite mort" - the little death), which can be immensely pleasureable and satisfying for males. Each spurt is associated with a wave of sexual pleasure, especially in the penis and loins. The first and second convulsions are usually the most intense in sensation, and produce the greatest quantity of semen. Thereafter, each contraction is associated with a diminishing volume of semen and a milder wave of pleasure. During sexual intercourse or masturbation, most males will find it difficult to resist the psychological temptation to continue the stimulation of the penis to the point of ejaculation once the feeling of orgasm becomes imminent. During the process, males may make involuntary vocalizations such as grunting, moaning, groaning, or crying out, and some may experience full body convulsions, the spasms in tempo with those in the penis.