Factors which affect the superconducting transition temperature (Tc) of thin tin films are of considerable importance in the design of thin film devices. This paper reports an investigation of one such factor, the stress state of the film. Two approaches were used. First, the transition temperature was correlated with the differential thermal contraction between film and substrate. Six different types of glass were used for substrates, and the six films were evaporated simultaneously to ensure similar conditions of evaporation. Secondly, a substrate‐bending technique was used to stress the film while holding it near its transition temperature. For both of these methods, shifts of the transition temperature greater than 0.1°K have been observed. However, it was found that agglomeration of the film can greatly reduce the dependence of the transition temperature on stresses transmitted to the film by the substrate.When agglomeration was negligible, both these approaches yielded a linear increase inTcwith tensile strain. Values fordlnTc/dlnvwere obtained, wherevis the volume of the tin film. The average values were +8.6 from the differential thermal contraction measurements, and +8.1 from the substrate bending measurements. These results are in reasonable agreement with the properties of bulk tin (dlnTc/dlnv=+7.5). However, the films were able to withstand tensile stresses more than an order of magnitude greater than the elastic limit of bulk tin and still recover their original properties upon relaxation.