  An exact one parameter ($\alpha$) family of solutions representing scalar
field collapse is presented. These solutions exhibit a type of critical
behaviour which has been discussed by Choptuik. The three possible evolutions
are outlined. For supercritical evolution (when black holes form) I show that a
quantity related to the mass of the black hole exhibits a power law dependence
on $\alpha$, for near critical evolution $M \simeq |\alpha-\alpha_{\rm
crit}|^{1/2}$. Based on the properties of the solution some comments are also
made on conjectures of Choptuik.
