A top contact metallization of a photovoltaic solar cell collects the current generated by incident solar radiation. Several power-loss mechanisms are associated with the current flow through the front contact grid. The design of the top metal contact grid is one of the most important areas of efficient photovoltaic solar cell design. In this paper, an approach based on the constructal theory is proposed to design the grid pattern in a photovoltaic solar cell, minimizing total resistive losses. Constructal theory explains the geometric form (shape and structure) of most volume-to-point systems in nature. In this paper, the applicability of the constructal theory to design top contact metallization for a photovoltaic solar cell has been extended.