A simple and cost effective spectrophotometric method was described for the determination of Imipenem in pure form and in pharmaceutical formulations. The method is based on the formation of colored chromogen when the drug reacts with brucine and sodium periodate in acidic medium. This method was applied for the determination of drug contents in pharmaceutical formulations and enabled the determination of the selected drug in microgram quantities (0.5 to 3.0 mL). No interferences were observed from excipients and the validity of the method was tested against reference method. The colored species has an absorption maximum at 520 nm for Imipenem and obeys beer’s law in the concentration range 0.02-0.12 mg/mL of Imipenem. The apparent molar absorptivity was 61X10-5 and sandell’s sensitivity was 7x10-4. The slope is 0.0230 ± 0.0008, the intercept of the equation of the regression line is 0.0230 ± 0.0008. The optimum experimental parameters for the reaction have been studied and the validity of the described procedure was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed method was successfully applied for the determination of Imipenem in pharmaceutical formulations.