SUMMARY
Fifty patients were examined by ascending phlebography of both legs in a prospective, double‐blind, within‐patient series. Each leg was randomly allocated to the examination using either iohexol 300 mg I/ml or ioxaglate 320 mg I/ml as the contrast medium. Immediate side effects were recorded in all patients, and delayed effects in 40 patients. Statistical analysis using the chi‐square test showed no significant difference in the immediate or late side effects of either medium, and there was no difference in film quality. It is concluded that both iohexol and ioxaglate are well tolerated for phlebography and both are acceptable media for this examination.