Pepper mild mottle virus (PMMoV) was obtained from naturally infected pepper (Capsicum annuum L.). Plants with mosaic, puckering and mottling yellow or light green symptoms on the upper developing leaves were collected from the Mecca regions, Kingdom of Saudi Arabia. Infected samples were carefully tested by direct enzyme-linked immunosorbent assay (ELISA) with antiserum to Tobacco mosaic virus (TMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), Tobacco etch virus (TEV), Tomato spotted wilt virus (TSWV) and Pepper mild mottle virus and confirmed by electron microscopy and reverse transcription-polymerase chain reaction (RT-PCR) assay. On the other hand, we studied inhibitory effects of the novel synthetic chemical compounds from Pyrazolopyrimidine against PMMoV and important human pathogens. We found that the efficacy of the antiviral agent depends on the capability of the virus to replicate itself by stopping the viral messenger RNA replicate and thus prevent the spread of the virus in infected pepper plants when plants were treated with Pyrazolopyrimidine compounds after 24 h from PMMoV inoculation.