Deposition of gold on copper from acid gold bath was investigated using electrochemical and microscopic techniques. The growth morphology of both soft and hard gold deposits was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Analysis of chronoamperometric transients showed that the mechanism of nucleation and growth of hard gold is three-dimensional progressive nucleation and growth of right-circular cones. This was further confirmed by SEM and AFM measurements. The grain size of hard gold deposit was shown to be much smaller than that of soft gold, indicating that nickel in deposit acts as a grain refiner. The mean roughness of hard gold deposit increases with deposition time, and with an increase of negative potential from -0.5 to -0.70 V (vs SCE), however, the surface becomes more uniform at -0.80 V. Similarly, the maximum height of clusters increases as potential is made more negative between -0.50 and -0.65 V, while it decreases steeply at potentials from -0.65 to -0.80 V. The inhibition of crystal growth in gold deposition at certain potentials was observed electrochemically and corroborated by microscopic techniques.