A mathematical analysis has been made of the current distribution beyond the edge of the contact in a stripe contact injection laser structure. An analytical solution is obtained for this distribution using a simplified but reasonably accurate model. For a typical stripe-contact laser, the junction current beyond the contact region is equivalent to the current at threshold through an additional stripe width of the order of 10 μm. As a result of such current spreading, lasers with narrow stripe-contacts will have greatly increased apparent threshold current densities. © 1973.