Corrosion resistance performance of unheated and heat treated duplex () brass in different nitric acid concentrations was investigated. Gravimetric and potentiodynamic polarization methods were used for the corrosion measurement and assessment. The polarization experiments were performed using a Digi-Ivy potentiostat at the ambient temperature of 28 degrees C. Tafel and polarization resistance techniques were used to estimate the corrosion rate, the polarisation resistance and the inhibition of the experimented alloy samples. Similarly, the gravimetric (weight loss) method was used to estimate the samples metal loss and the corrosion rate. The results obtained showed the susceptibility of unheated and heat treated duplex () brass in the nitric acid concentrations. Overall, the untreated alloy gave better performance for most of the HNO3 acid concentrations.