In recent years, cold atoms could prove their scientific impact not only on ground but in microgravity environments such as the drop tower in Bremen, sounding rockets, and parabolic flights. We investigate the preparation of cold atoms in an optical dipole trap, with an emphasis on evaporative cooling under microgravity. Up to 1 ×106 rubidium-87 atoms were optically trapped from a temporarily dark magneto-optical trap during free fall in the drop tower in Bremen. The efficiency of evaporation is determined to be equal with and without the effect of gravity. This is confirmed using numerical simulations that prove the dimension of evaporation to be three dimensional in both cases due to the anharmonicity of optical potentials. These findings pave the way towards various experiments on ultracold atoms under microgravity and support other existing experiments based on atom chips but with plans for additional optical dipole traps such as the upcoming follow-up missions to past and current space-borne experiments.