With the aim of evaluating the possible impacts of cold plasma on the structure and growth pattern of Capsicum annuum, the current study was carried out. The seeds were exposed to an argon-derived plasma(0.84 W cm~(-2) surface power densities) for 0, 1 or 2 minutes. Plasmatreated seeds were grown in the Murashige and Skoog(MS) medium or MS medium supplemented with BA and IAA. The presence of purple stems was recorded in plasma-treated plants grown in the medium supplemented with hormones. The recorded morphological differences were dependent on the exposure time of plasma treatments and/or the presence of hormones in the culture media. Plasma treatment of 1 minute had an improving effect on the shoot and root lengths as well as total leaf area, whereas plasma treatment of 2 minutes had an adverse effect. In contrast to the 1 minute treatment, plasma treatment of 2 minutes significantly impaired growth and hence reduced the total biomass. Alterations in stem diameter and differences in tissue patterns(especially in the vascular system) occurred, and were mainly dependent on the plasma exposure time and/or the presence of hormones. This is a first report on the effects of cold plasma on plant growth in in vitro conditions. With the aim of evaluating the possible impacts of cold plasma on the structure and growth pattern of Capsicum annuum, the current study was carried out. The seeds were exposed to an argon-derived plasma (0.84 W cm -2 surface power densities ) for 0, 1 or 2 minutes. Plasmatreated seeds were grown in the Murashige and Skoog (MS) medium or MS medium supplemented with BA and IAA. The presence of purple stems was recorded in plasma-treated plants grown in the medium supplemented with hormones . The recorded morphological differences were dependent on the exposure time of plasma treatments and / or the presence of hormones in the culture media. Plasma treatment of 1 minute had an improving effect on the shoot and root lengths as well as total leaf area, Treatment of 2 minutes had an adverse effect. In contrast to the 1 minute treatment, plasma treatment of 2 minutes significantly impaired growth and hence reduced the total biomass. Alterations in stem diameter and differences in tissue patterns (especially in the vascular system) occurred, and were mainly dependent on the plasma exposure time and / or the presence of hormones. This is a first report on the effects of cold plasma on plant growth in vitro.