This thesis presents the results of a priliminary study on the effecct of laterite on mortar and concrete. Laboratory experiments aare carried out to look into the influence of laterite content (as percentage of ccement replacement ) on workability, sterngth, shrinkage, porosity and microstructure of mortar. The pozzolanic activity of laterized mortar is examined using a thermogravimetric technique. Preliminary results show that increasing laterite content up to 30% decreases the compressive strength of laterised concrete and mortar, and significantly affect other properties of mortar, and significantly affect other properties of mortar. Laterite is shown reacting with hydroxide but this type of reaction did not show any contribution to the strength development of mortar and concrete although workability in term of cohesive increase with laterite content.