In order to study the effect of bio-fertilizer, tillage practices and weed control methods on weed density, yield and economics of Mung bean a farmer’s participatory trail was conducted during Zaid season of 2013 and 2014 on the farmers’ field at Manjosh village in Jamui district (Bihar). The experiment consisted of two tillage practice (zero tillage and conventional tillage) and herbicide (application and no application) along with Rhizobium inoculation and un-inoculation in factorial randomized block design with three replication. Minimum weed density and weed dry weight and maximum weed control efficiency was recorded by zero tillage method of sowing. However, maximum grain yield, stover yield, gross return, net return and B:C ratio was also recorded by above respective treatment during both the years of experiment and in pooled. Application of Pendimethalin at 1.0 kg ha^-1 was recorded minimum weed density and weed dry weight with higher weed control efficiency and also gave maximum grain yield, stover yield, gross return, net return and B:C ratio during both the years of experiment and in pooled. Seed treatment with Rhizobium was also recorded maximum performance of yield and economics with minimum weed density and dry weight during both the years of experiment and in pooled.