AIM: The therapeutic approach to differences of sex development (DSD) has changed over recent decades. We aimed to describe the evolution of clinical diagnoses of DSD in children attending a tertiary paediatric centre. METHODS: This retrospective observational study compared diagnoses and management, before and after the introduction of consensus guidelines for DSD in 2006. RESULTS: The cohort included 87 patients with 46, XY (78.4%), 15 with 46, XX (13.5%) and 9 with sex chromosomal DSD (8.1%). Gonadectomy rates were 27.9%, 6.6% and 66.6% for the respective groups. The mean age at presentation was younger among those with 46, XY than with 46, XX (0.5 ± 2.5 vs. 6.8 ± 8.1 years, p = 0.007) and a higher proportion presented by age one year (93.1% vs. 60.0%, p = 0.001). During 1990-2006, 44 children were diagnosed, and during 2007-2019, 67 children. Prenatal diagnosis increased from 4.5% to 25.4% (p = 0.004). Smaller proportions in the later than earlier period underwent gonadectomy (19.4% vs. 40.9%, p = 0.017) and sex reassignment (1.5% vs. 13.6%, p <
0.02). CONCLUSION: Over the three-decade period, the rate of prenatal diagnosis increased and the rates of gonadectomy and sex reassignment declined. These findings reflect a shift towards earlier, individualised multidisciplinary care, which was facilitated by advanced diagnostics.