  We report the single crystal growth and anisotropic magnetic properties of
the tetragonal RAg$_2$Ge$_2$ (R = Pr, Nd and Sm) compounds which crystallize in
the ThCr$_2$Si$_2$ type crystal structure with the space group \textit{I4/mmm}.
The single crystals of RAg$_2$Ge$_2$ (R = Pr, Nd and Sm) were grown by
self-flux method using Ag:Ge binary alloy as flux. From the magnetic studies on
single crystalline samples we have found that PrAg$_2$Ge$_2$ and NdAg$_2$Ge$_2$
order antiferromagnetically at 12 K and 2 K respectively, thus corroborating
the earlier polycrystalline results. SmAg$_2$Ge$_2$ also orders
antiferromagnetically at 9.2 K. The magnetic susceptibility and magnetization
show a large anisotropy and the easy axis of magnetization for PrAg$_2$Ge$_2$
and NdAg$_2$Ge$_2$ is along the [100] direction where as it changes to [001]
direction for SmAg$_2$Ge$_2$. Two metamagnetic transitions were observed in
NdAg$_2$Ge$_2$ at $H_{\rm m1}$ = 1.25 T and $H_{\rm m2}$ =3.56 T for the field
parallel to [100] direction where as the magnetization along [001] direction
was linear indicating the hard axis of magnetization.
