In this paper, an experimental investigation on the effect of ternary blending on the various properties of cement paste and mortar has been reported. The ternary blended cements have been prepared by using one type of clinker and two types of pozzolans. Two types of grinding techniques, two different fineness values and varying amounts of additives have been employed. Besides these, control pastes and mortars are prepared. The influence of fineness, different grinding techniques and other parameters on the strength of the ternary blended cements has been evaluated. The chemical compositions of the pozzolans are consistent with the requirements given in both the TS 25 (a Turkish standard) and ASTM C 168 standards. The results indicate that the basaltic pumice used in this study, taken from the Osmaniye-Adana province (Southern Turkey), can be used as an admixture in cement production. SEM, XRD and thin section analyses showed that a large quantity of sheet-like CSH was formed when a combination of basaltic pumice and slag were incorporated in the mortar.