Let $G=(X,Y,E)$ be a bipartite graph. A subset $S$ of $X$ is a complement free dominating set if $S$ is an $X$-dominating set and $X-Y$ is not an $Y$-dominating set. A subset $S$ of $X$ is called a minimal complement free dominating set if any proper subset of $S$ is not a complement free dominating set. The minimum cardinality of a minimal complement free dominating set is called the complement free domination number of $G$ and is denoted by $\gamma_{cf}(G)$. In this paper some results on complement free domination number are obtained.