Glucose-6-phosphate dehydrogenase deficiency is an erythrocyte enzyme disorder caused by mutations in the G6PD gene, which has an X-linked inheritance. Here we analyze the clinical and laboratory characteristics of 24 subjects with G6PD deficiency over 25 years. Their median age at diagnosis was 10.2 years (range: 0.6-56.4). No symptoms were observed in 54.2 % of patients, whereas 25 % had chronic non-spherocytic hemolytic anemia; 12.5 %, neonatal jaundice and postinfectious hemolytic anemia; and 8.3 %, acute hemolytic anemia after ingestion of fava beans. The 24 studied patients had variants that had been previously described in the bibliography. The clinical characteristics observed here were consistent with the variants found. A total of 21 women from the maternal line of affected subjects were identified as deficiency carriers using molecular biology techniques, so they received the corresponding genetic counseling.