Extraction of nematodes from plant roots is a very time- and labour-intensive process, so new methods offering advantages for either speeding or lessening workloads are highly desired, but must be tested before adoption. This paper reports a novel method for extraction of nematodes using ultrasonic waves that is fast and simple. It is also non-destructive to roots, and whole root systems can be sampled for migratory endoparasitic nematodes. The method was tested and optimized for extraction of Burrowing Nematodes (Radopholus similis) from the roots of the aquatic plant Anubias sp. in water. Different durations of treatment and ultrasonic frequencies were tested, and the number of nematodes and plant damage recorded. The highest extraction efficiencies per sample were obtained after 40 min or longer sonication at a frequency of 40 KHz, but the condition of the extracted nematodes was poor for identification at these long durations. Considering efficiency as number of nematodes extracted per unit time, optimal extraction was obtained with a duration of 20 min at a frequency of 40 KHz. With this duration there was little observable damage to nematodes (allowing use in experiments or inoculation trials), or plants (so that successfully replanting is possible). The ultrasonic method was compared with other extraction techniques, and was much more efficient than root incubation, shaking or mist chamber techniques, but a little less efficient per sample than the maceration-centrifugal-flotation method. The ultrasonic method is suitable for extracting migratory endoparasites and semi-endoparasites from plant roots. If present, ectoparasites are also extracted. Ultrasonic extraction requires less time and effort for root preparation than other methods, so it can be a lower cost method for routine use. Furthermore, it can be incorporated into a simple, cheap, mass-manufactured, portable and automated kit, which can be made widely available, so that the technique can be widely used.