The potential of using the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci (Gennadius) has been established in previous laboratory studies. However, laboratory studies can overestimate the level of control achieved by biocontrol agents in the glasshouse. Glasshouse trials are therefore required to confirm laboratory results before full-scale commercial development is considered. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci (>90% and >80%, respectively) was recorded after application of S. feltiae. The efficacy of the biocontrol agent at various application rates was also investigated, where halving the rate of S. feltiae application caused no significant reduction in B. tabaci mortality on tomato foliage. Steinernema feltiae has shown much potential for incorporation into integrated pest management strategies for the control of B. tabaci.