The linkage between endometriosis and galactose-1-phosphate uridyl transferase gene (GALT) mutations is controversial. In this study, the prevalence of the most common GALT mutations, Q188R and N314D, was assessed in women with endometriosis in a Chinese population. Three hundred twenty five unrelated women with endometriosis were enrolled. Samples of umbilical cord blood obtained from 310 female newborn infants were used as population controls. Genomic DNA isolated from endometriosis patients and controls were subjected to multiple polymerase chain reactions to determine the Q188R and N314D mutations. There was no significant difference in the frequencies of the Q188R and N314D mutations between endometriosis patients and controls. The endometriosis patients were further divided into subgroups of stage III and IV disease, but still no statistically significant differences were observed in the frequency of the Q188R and N314D mutations between any of these groups and the controls. These findings suggest that Q188R and N314D mutations are not likely to be associated with an increased risk of endometriosis among Chinese Women.