As many oil fields go into their final stage of production, new technologies are necessary in order to maintain the production and increase the recovery of hydrocarbons. In recent years, nanofluids (suspended nanoparticles in brine) have been launched as a cheap, efficient, and environmentally friendly alternative to other methods. This work concerns the application of SnO2 nanoparticles to increase the efficiency of a water flooding in heavy oil core flooding system. SnO2 nanoparticles were dispersed in brine solution at different levels of concentration and their effect on wettability change was investigated. Contact angle measurements showed that the rock wettability changed from oil-wet to water-wet condition after treatment with nanoparticles. Scanning electron microscopy (SEM) results showed homogenous deposition of nanoparticles onto core plug surface. Interfacial tension (IFT) was also noticeably reduced in presence of nanoparticles. Water flooding experiments showed that increasing the nanoparticle concentration up to 0.1% increases the recovery but further increase to 0.5% reduces the effect on recovery.