For two graphs G and H, the direct product G×H is the graph with vertex set V(G)×V(H) and two vertices (g₁,h₁) and (g₂,h₂) are adjacent whenever g₁g₂ is an edge in G and h₁h₂ is an edge in H. The Wiener index of a connected graph G, denoted by W(G), is the sum of the distances between all unordered pairs of vertices of G. In this paper, we obtain the Wiener index of the direct product of a path and a generalized Petersen graph P(m,3).