An enormous amount of waste materials is generated during mineral processing, power generation and metallurgical processes. The surface disposal of tailings and coal ash creates numerous environment related problem. The worldwide application of backfilling in underground mines has resolved several issues associated with surface tailings disposal and underground mining operations. Cemented backfilling in India is in a fledgling stage and it has a virtuous scope of application in most of the underground mines. Uniaxial compressive strength (UCS) is one of the essential backfill design parameters. The in-situ backfill strength development after pouring into the stope is one of the essential criteria of backfill performance in field. Limited studies about the backfill strength development in in-situ conditions are available in literature. Hence, the in-situ cured backfill strength was determined in three underground hard rock mines with four different backfilling methods. Out of these, three cases have shown reduction in UCS as compared to lab prepared specimens by 9–33%. Only in one instance higher UCS was observed as compared to lab-based result.