In a prospective randomized study of 417 patients, side effects and complications of contrast media and the diagnostic quality of images obtained after hysterosalpingography (HSG) were evaluated after use of diatrizoate meglumine (104 patients), ioxaglate (105 patients), iohexol (105 patients), or ethiodized poppy-seed oil (103 patients). The authors detected no differences among these groups in the prevalence of pain during HSG. The prevalence of lower abdominal pain and vaginal bleeding after HSG was significantly lower in the group that received ethiodized poppy-seed oil than in the three other groups. The prevalence of pelvic infection or inflammation was significantly lower with ethiodized poppy-seed oil than with water-soluble media. All contrast media provided acceptable diagnostic image quality with regard to fallopian tubes, peritoneal spill, and intraperitoneal distribution. Visualization of the uterine cavity and ampullary rugae was significantly better with water-soluble media than with ethiodized poppy-seed oil, which was associated with a high conception rate and which the authors consider preferable for HSG.