The purpose of this study is to investigate the relationship between the blood level of cadmium and the occurrence of ectopic pregnancy. Forty-one (41) case patients with ectopic pregnancy and 41 uncomplicated intrauterine pregnant patients as controls were recruited. The concentrations of cadmium (Cd) were measured from blood samples using atomic absorption spectrometry. The cases and controls were similar in age, body mass index, and smoking habits. The median blood level of Cd was 0.32 mu g/l (interquartile range [IQR] 0.00-0.71) in the women with ectopic pregnancies and 0.34 mu g/l (IQR 0.09-0.59) in the controls. There was no significant association between blood cadmium levels and ectopic pregnancy.