This study estimated the efficacy of sublingual nifedipine 10 mg vs. sublingual lacidipine 4 mg in the management of hypertensive crises. We studied 40 patients with diastolic blood pressure > or = 120 mm Hg, who were divided into two groups of 20. Blood pressure and heart rate were assessed in the recumbent position before treatment and after 30, 120, and 240 min. Comparison of the effectiveness of these drugs was analyzed by Student's t test. Both drugs tested revealed a statistically significant hypotensive effect on diastolic and systolic blood pressure, and few side effects. Compared with lacidipine, nifedipine had a greater hypotensive effect on diastolic and systolic blood pressure in the first 30 min and on the diastolic blood pressure after the first 120 min. However, the hypotensive effect of lacidipine is statistically significant. After 4 h, both drugs showed a similar efficacy without significant statistical variations. We concluded that in the management of hypertensive crises the use of each of these drugs can have a particular range: nifedipine can be used when a pronounced and rapid blood pressure decrement is necessary, whereas lacidipine can be used when a more gradual effect is preferable.