This study examines the influence of aggregate types on the unit weight and strength characteristics of lightweight concretes (LWC). In this study, a scoria aggregate light weight concrete (SLWC), a pumice aggregate light weight concrete (PLWC) and three scoria-pumice commixture aggregate light weight concretes (SPLWC-I, SPLWC-II and SPLWC-III) were produced. Average dry unit weights of SLWC, SPLWC-I, SPLWC-II, SPLWC-III and PLWC mixtures were 1997, 1696, 1638, 1477, 1368, kg/m(3), respectively. Compressive and flexural tensile strength and unit weight of concrete were determined at 28 days. SLWC, SPLWC-I, SPLWC-II, SPLWC-III and PLWC mixtures developed 44.1, 30.5, 27.6, 23.3, 15.8 MPa compressive strength, respectively, which satisfy the load bearing requirements. In terms of strength and unit weight requirements, all concrete produced can be classified as well as used as a LWC.