Present study was designed to establish in-vitro and in-vivo correlation (IVIVC) of two immediate release tablet formulations of 400mg Norfloxacin [Drug A as test and Drug B as reference]. Dissolution study was conducted in 0.1 N HCl using USP apparatus II. In-vivo evaluation was carried out in 18 healthy humans according to a single dose, two-sequence, and cross-over randomized with a wash-out period of one week. After dosing, serial blood samples were collected for a period of 10 hours. Plasma harvested from blood, was analyzed for norfloxacin by a sensitive, reproducible and accurate HPLC method. Various pharmacokinetic parameters were determined from plasma concentrations for both the formulations. Non-significant difference was found for test/reference ratio of these parameters and the value of F was found to be 0.99 which is in good agreement with the limits given in FDA and WHO guidelines for such parameters. Difference factor (f(1)), similarity factor (f(2)) and level A IVIVC were evaluated showing that drug A is bioequivalent to drug B.