Abstract <p>In this study, different nano coatings were prepared using two main resins: Epoxy (Ep) and unsaturated Polyester (UPE). Nano titanium oxide (TiO₂), nano aluminium oxide (Al₂O₃) and nano clay were added in 1 and 4 wt % fractions by hand lay-up method. Surface roughness and anti-bacterial activity were tested on the coated specimens. The results showed that the addition of nanoparticles increased roughness for both epoxy and polyester at 4 wt % ratio, with the highest value noticed for polyester reinforced with 4 wt % of nanoclay (3.268 µm). The anti-bacterial activity of the surfaces on isolates of <i>Escherichia coli (E. coli)</i> and <i>Staphylococcus aureus (S. aureus)</i> showed that the increase of nanoparticles for both epoxy and polyester led to enhancement in inhibition rate. Generally, the highest inhibition rates were 90% for <i>E. coli</i> bacteria for polyester coating with 4 wt % of TiO₂, also with 1 wt % additive the inhibition rates were 66%, while at epoxy with 4 and 1 wt % for the same type of bacteria the inhibition rates were 44 and 26% respectively. In <i>S. aureus</i> bacteria the inhibition rates bacteria for polyester were 56.80% with 4 wt % and 45.40% with 1 wt %, while there is no inhibition rates for epoxy for the same additive and bacteria type. In Al₂O₃ additives the inhibition rates for <i>E. coli</i> bacteria in polyester were 80 and 64% at 4 and 1 wt % additives respectively. Similarly at epoxy the inhibition rates were 32 and 42% at 4 and 1 wt % additives correspondingly. While the inhibition rates for <i>S. aureus</i> bacteria in polyester were 81.80 and 56.80%. But there are no inhibition rates for epoxy for the same additive and bacteria type. When adding nanoclay, there is no inhibition rates for epoxy and polyester with both <i>E. coli</i> and <i>S. aureus</i> bacteria.</p>