Purpose: Patients with mixed gonadal dysgenesis (MGD) and ovotesticular disorders of sex development (DSD) usually present with asymmetric gonads. Differential diagnosis of these conditions is based on karyotype and pathological findings of gonads. However, it is difficult to determine sex of rearing and to predict long-term outcomes. This study investigated the clinical features, karyotype, sex of rearing, and pubertal outcomes of patients with MGD and ovotesticular DSD. Methods: This study included 17 patients with DSD who presented with asymmetric gonads. Presenting features, karyotype, sex of rearing, and pubertal outcomes were reviewed retrospectively. Results: All 17 patients presented with asymmetric gonads in the neonatal period. They manifested labioscrotal deformity (58.8%), hypospadias (52.9%), clitoromegaly (23.5%), and micropenis (11.8%). Eight patients with a dysgenetic gonad and a testis were diagnosed with MGD; karyotype was 45,X/46,XY in 7 (87.5%) and 45,X/47,XYY in one patient (12.5%). Nine patients with a coexistence of testicular and ovarian tissues were diagnosed with ovotesticular DSD; karyotype was 46,XX in 6 (66.7%), 45,X/46,XY in 2 (22.2%) patients, and 46,XY in one patient (11.1%). Mullerian duct remnants were found in 15 of 17 patients (88.2%). Fifteen patients underwent unilateral gonadectomy; 11 of them raised as males and 4 patients were reared as females. The remaining 2 patients underwent bilateral gonadectomy and raised as females. Six of 8 patients with MGD (75%) were raised as males, while 5 of 9 patients with ovotesticular DSD (55.6%) were assigned as males. Two patients with MGD and two with ovotesticular DSD reached pubertal age. Among them, one phenotypic male with MGD and two with ovotesticular DSD showed spontaneous puberty. The remaining one female with MGD showed hypergonadotropic hypogonadism and have been treated with estrogen replacement therapy. One male-assigned patient with ovotesticular DSD was confused about sexual identity at age 20 years and changed gender as a female, despite her karyotype of 46,XX. Conclusions: DSD with asymmetric gonads could manifest wide phenotype of external genitalia and karyotypes. Pathological findings of gonads are necessary for differential diagnosis of MGD and ovotesticular DSD. Further studies are needed to establish appropriate treatment strategies and gender outcomes.