The performance of gold nanoparticles electrodeposited on boron doped diamond (BDD) electrodes was investigated in respect to the reduction of chloramphenicol (CAP), an antibiotic of the phenicols family. The chosen deposition protocol, three nucleation-growing pulses, shows a remarkable surface coverage, with an even distribution of average-sized gold particles (similar to 50 nm), and it was proven capable of generating a three-fold increase in the CAP reduction current. A calibration plot for CAP detection was obtained in the micromolar range (5-35 mu M) with good correlation coefficient (0.9959) and an improved sensitivity of 0.053 mu A mu M-1 mm(-2) compared to the electrochemistry of CAP at a bare BDD electrode.