ABSTRACT: The behavior of concrete hollow block masonry prism plastered with steel fiber reinforced mortars with nanosilica under axial compressive load is investigated experimentally and numerically using nonlinear finite element simulation. Eight prisms 400 mm length × 400 mm height × 100 mm thickness, consisting of two layers hollow concrete blocks joined together by normal mortar were subjected to compressive load until failure. Two control specimens without plaster, three specimens plastered using steel fiber reinforced mortar with nanosilica having thicknesses of 10 mm, 20 mm and 30 mm and three specimens without nanosilica in the mortar were tested under compressive load up to failure.