Lantana camarais a noxious invasive plant that invades agricultural and natural ecosystems. In the current study, phytotoxicity of hexane and ethanolic leaf extracts ofL. camarain different concentrations and soils invaded by it onLepidium sativumwere investigated under laboratory conditions. Soil toxicity was evaluated by comparing the growth ofL. sativumon soils sampled fromLantana-invaded andLantana-free sites. Results showed that extract concentrations and solvent type and their interaction significantly reduced percent seed germination and seedling growth. Compared to control (distilled water), both hexane and ethanol extracts at 5% w/v concentration significantly reduced percent germination and early seedling growth and completely inhibited seed germination at 10% w/v of hexane leaf extract, suggesting that hexane extract has a greater inhibitory effect than ethanolic extract in all the parameters measured. However, growth performance and seed yield ofL. sativumgrown on soil invaded byLantanadid not significantly vary from those grown on soils sampled from noninvaded sites. The results of this study generally showed that thoughLantanaleaf extracts have a direct negative allelopathic effect onL. sativum, soils invaded byLantanahave no toxic materials in the soil to directly or indirectly inhibit the growth ofL. sativum. Further field studies on allelopathic effects ofLantanaonL. sativumare recommended.