Abstract: The effect of coloured plastic mulches on the control of root-knot nematode (Meloidogyne javanica Treub) infections on tomato (Solanum lycopersicum) was investigated at the Federal College of Agriculture Ishiagu, Ebonyi State, Nigeria in 2009 and 2010 cropping seasons. Field experiments were performed in 2009 and 2010. The experiments were arranged in a factorial fitted into Randomized Complete Block Design (RCBD) with three replications. The varieties served as Factor A, while the coloured plastics served as Factor B. Tomato varieties used for the experiments were Ishiagu Local, Roma, Roma VF and UC82B. Black, blue and white coloured polyethene plastics of 3 mm thickness were used to randomly mulch the plots. The unmulched plots served as the control. Data were collected on number of galled roots and gall index per plant at harvest, plant height (cm) and number of leaves per plant at 50% anthesis, number of fruits and fresh fruit weight (g) per plant at harvest. All data collected were subjected to analysis of variance (ANOVA) using GENSTAT 3 EditionRelease7.2. Significant treatment means were separated using Least Significant Difference (LSD) at 5% level of probability. The coloured plastic mulches significantly (p<0.05) reduced the number of galled roots and gall indices per plant at harvest. Plants in the mulched plots significantly (p<0.05) produced higher plant heights, number of leaves, number of fruits and fresh fruit weights per plant. Black plastic mulch proved better than other plastic materials in all the parameters measured. Black plastic conserved heat around the root zone and raised the temperature of the soil to the disadvantage of the phytopathogenic nematodes. Black plastic mulch reduced significantly root knot nematode infections in Ishiagu local, Roma, Roma VF and UC82B varieties better than other mulching materials and is therefore, recommended.