This study was carried out to report the common causes of delayed puberty among female patients attending the Human Genetics Clinic, Medical Research Institute, Alexandria University in order to offer better management protocols and genetic counseling for these cases and their families. The study comprised 110 female patients aged over 13 years with delay in the onset of puberty or with variable degrees of development of secondary sex characteristics but with primary amenorrhea. According to the clinical, cytogenetic and biological data, the patients were classified into 3 groups. Group I: included 58 patients [52.7%] with hypergonadotropic hypogonadism; 42 patients [38.1%] had ovarian failure due to X chromosome abnormalities, 13 cases [11.9%] were found to have 46,XX ovarian failure and 3 cases [2.7%] had 46,XY gonadal dysgenesis. Group II: included 28 patients [25.5%] with hypogonadotropic hypogonadism; 13 cases [11.9%] with constitutional delay in growth and development, one [0.9%] had isolated hyperprolactinemia, 3 [2.7%] had thalassemia major, 5 [4.6%] had isolated growth hormone deficiency, one with Prader-Willi syndrome and 2 [1.8%] had pituitary microadenoma and group IlI: included 24 patients [21.8%] with eugonadism; 14 [12.7%] had Rokitansky syndrome, 6 [5.5%] had polycystic ovarian disease and 4 [3.6%] had complete androgen insensitivity. Somatic anomalies were relatively higher in patients with X-chromosome abnormalities [chromosomal incompetent ovarian failure] and Rokitansky syndrome.