We report new data on the Sb-136 6(-) yrast isomer with T-1/2 = 489(40) mu s and pi g(7/2)(1) x nu f(7/2)(3) configuration, populated in the projectile fission of U-238 on a Be-9 target. The analysis confirms the lifetime, providing a good accuracy measurement. In addition, the decay of the isomer to the ground state is newly suggested. Our result for the isomeric decay scheme is in a good agreement with shell-model calculations.