Introduction of vegetatively propagated Petunia hybrids since 1992 led to increasing virus infections of propagation material. Petunia hybrid ``Surfinia`` cultivated for pot-plant showed yellowing symptom along with stunt. Flowers were smaller in size and showed color-break symptom. Tobacco mosaic virus (TMV-pet) was isolated from the diseased petunia. Healthy petunia plants inoculated with TMV-pet induced mottle on leaves and color-break on flowers, and plants were stunted. Nucleotide sequences of coat protein gene amplified from RNA prepared from Nicotiana tabacum cv. Samsun infected with TMV-pet were determined (GenBank accession no. DQ981481). It showed 99.0% nucleotide sequence homology with TMV-potato3-2 (GenBank accession no. AF318215) isolated from potato showing yellow mosaic and stunt symptom, and with a TMV Korean strain (GenBank accession no. X68110). This is the first reported observation of TMV from vegetatively propagated petunia in Korea.