BACKGROUND: The purpose of our study was to evaluate the short-term effects of static stretching used during a warm-up, on vertical jump (VJ) performances. METHODS: Sixty high school and college volunteer students were tested after two different warm-up protocols: non stretching (NS) and static stretching (SS). Both protocols included the same general aerobic low-intensity warm-up for 8 minutes, carried out by the use of a treadmill. Forty-two were athletes and eighteen were recreationally active. SS consisted of 6 static stretching exercises for the extensor, flexor and adductor muscles of the lower limbs. Each stretch was held for 20 seconds and performed twice. VJ measurements with squat jump (SJ), countermovement jump (CMJ) and stiffness test (ST) were carried out immediately after protocols’ execution. The tests were performed using the OptoJump® machine. RESULTS: Data evidenced an impairment of jump height and flight time after SS compared to NS. Jump height was decreased in SJ P=0.001, in CMJ P=0.001 and in ST P=0.003. CONCLUSIONS: The results of the present study confirm that static stretching has detrimental effect on jump performance. Considered these results, it would be recommended not using static stretching during warm-up before performance related to the vertical jump ability.