A comparative, randomised, 12-week (two periods of six weeks) cross-over study including 150 patients (mean age: 63.4 years) suffering from stable but symptomatic (a minimum of three attacks per week) angina pectoris was performed in order to compare the effect on quality of life of two discontinuous nitrate treatments: transdermal 10 mg nitroglycerine patch (12 hours) and long-acting oral 40 mg isosorbide-5-mononitrate (once a day). The efficacy and safety were also compared. The two treatments equally and significantly improved patients' quality of life. The number of attacks and sublingual nitrate consumption significantly decreased under treatment. Attack severity was lower under nitroglycerine than isosorbide-5-mononitrate treatment. Finally, even though nitroglycerine more frequently induced headache than did isosorbide-5-mononitrate (13 cases versus 8), patients, and in particular those having received nitroglycerine treatment in the second period of the study, preferred the transdermal nitroglycerine treatment. In conclusion, results did not show any relevant difference in terms of efficacy or tolerability between the two treatments. Nevertheless, the facility of use and the feeling of protection were better under transdermal nitroglycerine patch than oral isosorbide-5-mononitrate treatment.