We have used a placebo controlled trial to investigate the effect of long-term administration of nifedipine in the prevention of symptomatic episodes of oesophageal spasm. Diary card scoring was used to assess symptoms in 8 patients with oesophageal spasm who were each given nifedipine and placebo for at least 6 weeks. No significant differences in symptoms between the nifedipine and placebo treatment periods were seen.