An extensive study was conducted during 2020 and 2021 in major zucchini production areas of Assiut, Egypt, where cucumber mosaic virus (CMV) is commonly found, to assess the incidence and prevalence of naturally infected some ornamental and weed species that could serve as CMV reservoirs. Cucumber mosaic virus has rapidly spread to cucurbitaceae farms in most regions of Egypt. More precisely, it has a wide host range causing severe damage in many important agricultural and ornamental crops. CMV was isolated from Zucchini plants (Cucurbita pepo) showing virus like symptoms. Cucumber mosaic virus was identified on the basis of symptoms, transmission, serology, transmission, electron microscopy (TEM) and reverse transcription polymerase chain reaction (RT-PCR). Coat protein (CP) gene was amplified using gene specific primer. In this study the CMV was transmitted into propagation host by mechanically and through aphids. The transmission was confirmed through direct antigen coating enzyme linked immunosorbent assay (DAC-ELISA). Isolation was performed depending on Chenopodium amaranticolor as a local lesion host. Virus was purified from 200 gm of virus-infected Nicotiana tabacum. Eighteen plants species belonging to twelve different plant families were studied as the hosts of CMV. Cucumber mosaic virus was detected in seven species only (Chenopodium amaranticolor, Nicotiana tabacum, Datura innoxia, Ocimum sanctum, Vinca rosa, Hibiscus rosa and Salvia splendens) by transmission viral isolate through mechanical and insect (Aphis gossypii) inoculation from naturally infected Cucurbita pepo with CMV.