Greenhouse and field trials were done to determine the potential of Heterorhabditis heliothidis (Khan, Brooks and Hirschmann) Poinar (NC19 strain), an undescribed Heterorhabditis sp. (NC447 strain), and Steinernema feltiae Filipjev (A32−6 strain) to control British Columbia populations of black vine weevil (Otiorhyncus sulcatus Fab.) and strawberry root weevil (O. ovatus L.). An outdoor application of H. heliothidis applied at rates of 500 and 5000 nematodes per litre of soil gave significantly better control of black vine weevil larvae on potted, lodgepole pine trees (Pinus contorta Dougl.) than did a diazinon drench. Under greenhouse conditions Heterorhabditis sp. NC447 was the most effective nematode of the three tested against O. ovatus on potted, Douglas-fir seedlings (Pseudotsuga menziesii (Mirb.) Franco) and S. feltiae the least effective, at all dose rates tested. A field trial using H. heliothidis against O. ovatus in a forest nursery did not provide a significant degree of weevil control. This lack of control is attributed to the average outdoor temperature (11 °C) during the treatment period, which was below the nematode’s optimum temperature range, and the higher-than-average rainfall.