An investigation was carried out into the effect of temperature on pressurised and pressureless tennis ball properties. Ball rebound from 100 inches, ball deformation, ball size, and ball coefficient of restitution of 25ms-1, 35ms-1 and 45ms-1 were measured for tennis balls at temperature between 0°C and 40°C. The low velocity rebound test was found to show more difference between ball constructions than the static deformation test or the high velocity coefficient of restitution test.