This study aimed at investigating the relation between the duration of sport practice DSP) and menstrual disturbance in adolescent female athletes; and at evaluating bone mineral density [BMD] in those with amenorrhea. 45 female athletes aged 13-22 years were the subjects of this study. They were selected to be practicing sport activity [PSA] at least 2 Hours/day, 6 days a week for a minimum of one year before and one year after the age of menarche. The athlete's age, weight, height, the sport activity starting age [SASA], the daily raining hours, age of menarche, and the presence or absence of amenorrhea and its duration were recorded. The BMD at the lumbar vertebrae was evaluated using DXA in 10 amenorrheic athletes. The results revealed that the SASA ranged from 6-15 years, and that the DSP ranged from 2-14 years. Amenorrhea [for 3-12 months] was found in 19 athletes [42%]. Comparing athletes with amenorrhea to those with eumenorrhea revealed a significant difference only regarding height and DSP [p < 0.01]. The athletes were divided into 2 groups; those PSA 2 hours/day [Group I] and those PSA 4 hours/day [Group II]. It was found that the number of amenorrheic athletes in group II [17 out of 24] was significantly higher than that number in group I [2 out of 21] [p < 0.01]. Also, the duration of amenorrhea correlated negatively with the SASA, but positively with the DSP in Group II [p < 0.05]. The BMD ranged from 85-119% compared to the mean of matched age, and there was a significant negative correlation between BMD and the DSP [p < 0.05].