Environmental concerns and several adverse effects of reliance on and improper use of pesticides make necessary the use of alternative methods. Allelopathy has a rather unexploited potential in integrated weed management and ought to be further studied. The allelopathic effects of velvet bean (Mucuna pruriens (L.) DC. var. utilis) on seedling emergence and first growth of the important weed rigid ryegrass (Lolium rigidum L.) were evaluated in a pot experiment conducted at Agricultural University of Athens. Leaf residues of velvet bean were used to determine their inhibitory potential on seedling emergence and growth parameters including height, leaf number, tillering and fresh and dry weight of rigid ryegrass. Moreover, the allelopathic potential of inflorescence residues of chia (Salvia hispanica L.) on rigid ryegrass was also evaluated. Our results revealed a significant weed suppressive ability of the studied plants. The plant residues incorporated into the soil significantly reduced the seedling emergence and growth parameters of rigid ryegrass as compared to the control. In particular, velvet bean's residues also reduced height, leaf number and biomass of rigid ryegrass up to 26, 51 and 62%, respectively. The indicated allelopathic activity of velvet bean and chia could be further exploited in future studies, by using either allelochemicals as models for future herbicides or the plants as useful cover crops or mulches in terms of integrated weed management.