An electrochemical study on two titanium alloys employed in orthopaedic implants - Ti6Al4V and Ti6Al7Nb - obtained through powder metallurgy (PM) was conducted in comparison with Ti6Al4V obtained conventionally. Samples were immersed in a simulated body fluid and incubated at 37°C for different times. The influences of processing method (PM or conventional) and composition on corrosion resistance were investigated. Corrosion resistance was evaluated with electrochemical impedance spectroscopy. All samples showed good reproducibility and high impedance modulus values approximately in the order of 106 Ω. Although no significant differences in the evolution of the corrosion behaviour over different immersion times were found, Ti-6Al-7Nb processed by PM delivered a steady growth of corrosion resistance from day one until twelve weeks of immersion and showed better performance between the two compositions and similar or superior corrosion resistance in physiological conditions to the alloy obtained conventionally. SEM revealed no evidence of pitting corrosion.