A field experiment was conducted under loamy sand soil during Kharif (rainy season), 2018 at Swami Keshwanand Rajasthan Agricultural University, Bikaner to evaluate the bio-efficacy of herbicides in clusterbean as affected by time of application. Results revealed that imazethapyr + imazamox at 50 g/ha as PoE (20 DAS) and pendimethalin + imazethapyr at 0.80 kg/ha as PE resulted in the lowest weed density and dry weight of both monocot and dicot weeds. Higher weed control efficiencies were also noted under these treatments. Plant height, pods per plant, seeds per pod and seed and straw yields, net returns and benefit: cost ratio were also superior with imazethapyr + imazamox at 50 g/ha as PoE (20 DAS) and pendimethalin + imazethapyr at 0.80 kg/ha as PE compared to the other treatments.