This document summarizes a research study that investigated the effect of fly ash and nano titanium dioxide on the compressive strength of concrete. Various concrete mixtures were prepared by partially replacing cement with fly ash (0%, 10%, 20%, 30%) and nano titanium dioxide (0%, 1%, 1.5%, 2%). The compressive strength of the concrete cubes was tested after 28 days of curing. The results showed that compressive strength increased up to 1.5% replacement of cement with nano titanium dioxide for all fly ash replacement levels. Maximum compressive strengths were achieved with 20% fly ash and 1.5% nano titanium dioxide replacement. The study concluded that nano titanium dioxide is effective in compensating for the early strength loss associated