A field trial was conducted at the Teaching and Research Station of University of Agriculture, Makurdi during the 2019 cropping season to investigate the effect of sawdust mixed with eucalyptus biochar on nematodes associated with beniseed as well as their impact on yield. A total of nine treatments combinations were evaluated using a 3 x 3 factorial experiment laid out in a Randomized Complete Block Design (RCBD) in three replications. The treatments combinations consisted of single applications of sawdust and eucalyptus biochar, and mixed formulations of sawdust + eucalyptus biochar applied in powder forms at the rates of 0 t/ha, 2.5 t/ha and 5 t/ha. Nematode and yield data were subjected to Analysis of Variance (ANOVA) and means were separated using Duncan’s New Multiple Range Test (DNMRT) at 5% level of probability. Results showed that use of 2.5 t/ha and 5 t/ha of sawdust mixed with eucalyptus biochar reduced the population of plant-parasitic nematodes by 21.6%, and 37.8%, respectively. Although yields obtained from plots treated with the two rates of mixed formulation were 0.51 t/ha and 0.49 t/ha, the observed difference was not statistically significant but was higher than yields obtained when either eucalyptus biochar or sawdust was applied singly. The study showed evidence of nematode population control and yield improvement when mixed formulations of sawdust-eucalyptus biochar was applied at 2.5 and 5.0 t/ha and hence recommended for inclusion in the integrated pest management program for beniseed production in Makurdi.