Systolic (SP), diastolic (DP), and mean arterial blood pressures (MAP) and pulse rate (PR) were recorded on treated and untreated conscious cynomolgus monkeys by the oscillometric method (Dinamap 1846SX/P). Each monkey was placed in a restraining tube with the cuff placed on the base on the shaved tail. Measurements were taken on untreated animals once or twice a day for 4 weeks. The mean and standard deviations for SP, DP, MAP, and PR were approximately 121 +/- 17, 60 +/- 14, and 84 +/- 17 mm Hg and 193 +/- 18 pulses/min, respectively. One male and one female cynomolgus monkey were treated with isoproterenol, norepinephrine, and nitroprusside. Blood pressure was measured indirectly with the cuff on the tail and directly with an indwelling catheter in the descending thoracic aorta. Although the oscillometric method was not as sensitive as the catheter, the oscillometric method detected a change in the same direction of SP, DP, MAP, and PR compared with the direct method for all drugs administered. The monitor was reliable and sufficiently accurate to conclude that it may be useful in toxicology studies for evaluation of blood pressure parameters in conscious cynomolgus monkeys.