Cucumber mosaic virus was found for the first time infecting pot marigold (Calendula officinalis) plants in Serbia, causing chlorotic mottling and leaf deformation symptoms. Samples collected from infected plants tested positive for Cucumber mosaic virus but not Impatiens necrotic spot virus using ELISA. Mechanical inoculation and RT-PCR further confirmed the presence of Cucumber mosaic virus. Sequence analysis showed the Serbian isolate shared 100% nucleotide identity with isolates from Poland, Italy and Serbia. This represents the first report of natural Cucumber mosaic virus infection in pot marigold in Serbia.