The effect of Sb on the homoepitaxial growth mode of a Ag(111) surface has been studied by scanning tunneling microscopy. In a previous paper we reported on the effect of Sb on the interlayer diffusion barrier of Ag(111). Here we describe in more detail the effect of Sb on the island nucleation and surface diffusion. We find a homogeneous effect of the Sb on the Ag(111) surface, while heterogeneous nucleation and sticking can be excluded. The surface diffusion barrier appears to be linearly dependent on the Sb concentration. This shows that Sb has an effect not only locally at the step edges, but also on the terraces where it decreases the mobility of the Ag atoms. Further, we show that the Sb segregates efficiently during growth.