The present study was carried out in a continuing experiment at the Bhadiarkhar farm of the CSK HPKV. Eight cropping systems were evaluated during 2016-17 for their effects on weed menace under mid hill conditions of Himachal Pradesh. There were 24 weed species, which invaded different cropping systems. During Kharif, Ageratum sp. (28%) Cynodon dactylon (20%) and Commelina benghalensis (19%) were the predominant weeds. In Rabi, Phalaris minor (63%) was the most dominating weed followed by Coronopus didymus (10%) and Spergula arvensis (6%). In traditional ‘rice-wheat’ system 14 species in Rabi and 8 in Kharif season were found associated and species richness varied with diversification of systems. In Rabi, the highest diversity of weed species was in rice-wheat system and in Kharif weed flora was more diverse in okra, turmeric and colocasia based systems and was lower in rice-based systems. During Kharif, Cynodon dactylon had the highest important value index (IVI) irrespective of the cropping system followed by C. benghalensis. Monochoria vaginalis was the important weed in rice-based cropping systems while Ageratum sp. was important in upland systems. Ageratum sp., Polygonum sp. and C. dactylon invaded the experimental field both during Kharif and Rabi. In Rabi, P. minor had the highest IVI in all the cropping systems.