Abstract: In this study 3 phytoseiid mite species were evaluated as biological control agents of Echinothrips americanus. The oviposition and predation rate of Amblyseius swirskii, Amblydromalus limonicus and Euseius gallicus were compared in a laboratory experiment. Moreover, A. swirskii and A. limonicus were compared as control agents of E. americanus on sweet pepper and rose plants in semi-field experiments. In the laboratory study A. swirskii showed a higher predation and oviposition rate than A. limonicus, while E. gallicus did not predate the first instar larvae of E. americanus and was therefore excluded from the semi field experiments. In the semi field experiment on sweet pepper plants the control of E. americanus was better with A. limonicus while A. swirskii built up a higher population. On rose plants, there was no difference between the two phytoseiid species.