We report 31 episodes of hypertensive crises in children, managed with sublingual nifedipine at the following dosages: 10 mg in children with body weight (BW) higher than 20 kg, 5 mg in children with BW between 10 and 20 kg, and 2.5 mg in children with BW below 10 kg. The mean initial blood pressures were 161.41 mm Hg for the systolic pressure (mSBP) and 111.25 mm Hg for the diastolic pressure (mDBP). After nifedipine, both the mSBP and the mDBP decreased, with onset of effect five minutes after dosage and maximum decrease at 60 min (mSBP 134.93 mm Hg, mDBP 79.23 mm Hg, for decreases of 16.4 and 28.7%, respectively), and this effect persisted for 180 min. Blood pressure increased again from min 240 to min 360, yet without reaching the initial levels. One case did not respond to the first dose of nifedipine and required a second one. The effect of nifedipine was more pronounced on the DBP than on the SBP, and greater reductions of both pressures were achieved in the cases with higher initial readings. No side of medication were observed in our patients.