Abstract A series of laboratory investigations were undertaken to evaluate the performance of concrete mixtures incorporating jarosite as partial replacement of fine aggregates. The effect of jarosite on the mechanical properties and durability has been investigated. Keeping the environmental suitability of concrete in mind, toxicity leaching characteristic potential test (TCLP) has been performed on raw jarosite and concrete samples. Different concrete mixes, prepared for three water-cement ratios and 5 jarosite replacement levels. One fourth of cement has been replaced by fly ash in all the concrete mixtures. When compared to the control mixes, encouraging results were obtained in the tests to determine the mechanical properties of the concrete containing jarosite. The other important aspect of concrete i.e. durability has been revealed as satisfactory. The leaching of jarosite in concrete mixtures has been observed within the permissible limits of United States Environmental Protection Agency (USEPA). The addition of jarosite as a partial sand replacement in concrete (along with fly ash as mineral admixture) up to 25% could be a new alternative feasible solution to its disposal issue. Also, the concrete with 15% jarosite as a sand replacement could be best suited for road and building construction purpose.