Nitroglycerin (glyceryl trinitrate, CAS 55-63-0, NTG) administered with an oral spray may be more effective in relieving anginal pain than sublingual tablets especially when the patient's mouth is dry. In this study, the effect of a NTG oral spray (Myocor Spray) on exercise-induced angina was compared with that of a sublingual tablet in relation to the oral dryness. In 17 patients with effort angina, graded bicycle exercise was performed twice at an interval of one week. Exercise was discontinued upon the onset of moderate anginal pain. Immediately after exercise, the oral dryness was evaluated by touching the tip of the tongue with a blotting paper for a moment. Then, 0.3 mg of NTG was administered by either a squirt of spray or a sublingual tablet in a randomized crossover fashion. Exercise results were reproducible between two exercise tests. According to the extent of the wet area of the blotting paper, the subjects were divided into two groups. In 7 patients of the wet group, the remission times of chest pain and ST segment depression were not significantly different by the formulation of NTG. In 10 patients of the dry group, however, both chest pain and ST depression more rapidly recovered with use of the oral spray (p < 0.05 and p < 0.05, respectively). These results strongly suggest that the NTG oral spray is superior to the sublingual tablet in relieving anginal attacks, when the oral wetness is decreased.