In July 2016, a serious stem necrotic disease was observed on chrysanthemum (Chrysanthemum morifolium) in a commercial greenhouse in Beijing, China. Most chrysanthemum varieties were infected, with a total disease incidence above 50%, rising to over 90% in some sensitive cultivars. Infected chrysanthemum plants exhibited two main symptoms: (i) irregular chlorotic spots on the upper leaves with shortened internodes (cultivar Silvia), or (ii) discontiguous black streaks on stems near the base of the upper petioles, followed by eventual dieback (cultivars Dante, Radost, Stellini, and Olive). These symptoms are very similar to those of chrysanthemum infected with the tospoviruses Tomato spotted wilt virus (TSWV) or Chrysanthemum stem necrotic virus (CSNV). Based on the results of reverse-transcription polymerase chain reaction (RT-PCR) assays, ELISA test and mechanical transmission, the causal agent was identified as TSWV. This is thought to be the first report of TSWV detected on chrysanthemum in China.