Vapor‐deposited nickel films in the thickness range 700 to 4000 Å were stressed to fracture in uniaxial tension in the as‐deposited condition and after annealing at 650°C for 3 h or at 700°C for 5 min. The existence of a strength dependence on thickness was observed for both the as‐deposited and annealed films; however, the as‐deposited films were 1½ to 2 times stronger than annealed films of comparable thickness. The thickness‐strength relationship for as‐deposited films was found to be &sgr; = 134 kg/mm2+(1675 Å kg/mm2)t−½, while that for the annealed was &sgr; = (−.0245 kg‐mm−2/Å)t+155.6 kg/mm2. Both the annealed and as‐deposited films exhibited fracture strengths in excess of bulk nickel of analogous structure.It is believed that the observed high strengths of as‐deposited nickel films are due in part to the high defect density arising from the vapor deposition process and to the proximity of the film surfaces which further inhibits dislocation motion. With regard to the latter, a mechanism involving dislocation pile‐up is proposed.