Abstract: In vivo bioavailaibility studies of nifedipine tablets were carried out in six healthy human subjects in fasting state and after a low-fat meal. A simple, reliable and rapid HPLC method of nifedipine estimation preceded by an extraction technique was employed for the determination of plasma and saliva nifedipine levels. Pharmacokinetic parameters were generated by computer application. The low fat meal taken appeared to reduce the absorption rate constant of nifedipine, in plasma and saliva from 0.96h-1�0.104 to 0.57h-1�0.168 and 0.86h-1�0.38 to 0.41h-1�0.03 respectively and increase the lag time in plasma and saliva from 0.13h�0.37 to 0.36h�0.58 and 0.17h�0.08 to 0.34h�0.18, respectively.