Let $G$ be a simple undirected graph with each vertex colored either white or black, $ u $ be a black vertex of $ G, $ and exactly one neighbor $ v $ of $ u $ be white. Then change the color of $ v $ to black. When this rule is applied, we say $ u $ forces $ v, $ and write $ u \rightarrow v $. A $zero\ forcing\ set$ of a graph $ G$ is a subset $Z$ of vertices such that if initially the vertices in $ Z $ are colored black and remaining vertices are colored white, the entire graph $ G $ may be colored black by repeatedly applying the color-change rule. The zero forcing number of $ G$, denoted $Z(G), $ is the minimum size of a zero forcing set.\\ In this paper, we investigate the zero forcing number for the generalized Petersen graphs (It is denoted by $P(n,k)$). We obtain upper and lower bounds for the zero forcing number for $P(n,k)$. We show that $Z(P(n,2))=6$ for $n\geq 10$, $Z(P(n,3))=8$ for $n\geq 12$ and $Z(P(2k+1,k))=6$ for $k\geq 5$.