This paper deals with a comparatively study of the engineering properties of the Oil-palm-boiler clinker (OPBC) OPBC and lightweight expanded clay aggregate (LECA) concretes. A grade 70 normal-weight concrete was designed as control mix. Normal weight coarse aggregate was substituted with OPBC and LECA up to 100% by volume, respectively. Their properties — workability, density, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and water absorption — were studied. Results showed that at the same mix proportion, all mixes exhibited acceptable workability, except for concrete containing LECA up to 75% onwards, which required the reduction of superplastisizer dozen to 16%. Mixes with 75% onwards LECA content exhibited acceptable workability. The oven dry density of concrete containing 100% OPBC and 50% LECA onwards, respectively, in this study can be considered as lightweight concrete. The use of saturated OPBC and LECA in concrete improves the mechanical properties of concrete under air drying condition. The ceiling strength of LECA concrete is at the early age of 7 days, whereas it happens to normal weight concrete and OPBC concrete at a later age. The water absorption of all mixes is below 3%, which can be considered as good concrete.