Placebo-controlled trials are not available to assess the efficacy of smooth muscle relaxants in the treatment of painful esophageal motility disorders. Therefore, we compared the effects of oral nifedipine (10-30 mg t.i.d.) and placebo in 20 patients (mean age 50 yr) with chronic noncardiac chest pain and the nutcracker esophagus in a 14-week double-blind crossover study. Compared to placebo, nifedipine significantly decreased distal esophageal contraction amplitude (mean +/- SEM, 198 +/- 11 mmHg to 123 +/- 9 mmHg; p less than 0.005), as well as duration and lower esophageal sphincter pressure. Nifedipine, however, was no better than placebo in the relief of daily chest pain frequency, severity, or index (frequency X severity) as assessed by patient diaries. Despite these disappointing results, long-term follow-up (mean, 16.6 mo) suggests these patients do improve. Mean daily chest pain index significantly (p less than 0.005) decreased from 10.3 +/- 2.0 at the beginning of the study to 3.2 +/- 0.8 at follow-up. Prescription drug use and physician visits for chest pain also significantly decreased. Distal esophageal contraction pressures significantly fell during the long-term follow-up but there was poor correlation with chest pain improvement. This study suggests that identification of the esophagus as the cause of chest pain coupled with supportive intervention may be more effective than drug therapy in improving these patients' chest pain.