Considered as a global common,outer space is a most valuable asset of the mankind for philosophical, pragmatic and scientific considerations. Rapid expansion of human activities in the outer space has posed a threat to the outer space environment and accordingly the protection of the outer space environment has emerged as a challenge of major importance for the global community as a whole. In this backdrop,an increased understanding of issues concerning the environmental impact of space activities and the need for the protection of outer space environment through international legal regulation and cooperative endeavours on the part of states and non-state actors has assumed paramount importance. The present study makes a humble attempt in this direction. It endeavours to give a coherent picture of the impact of space activities on environment and international legal measures for protection of the outer space environment and highlights the need for an international legal regime for the protection of the outer space environment.