The self propelled weeder was designed, developed and tested on the basis of agronomic and machine parameters at the College of Agricultural Engineering, University of Agricultural Sciences, Raichur. The main feature of prototype self propelled weeder were, a 4 hp petrol start kerosene run engine, power transmission system, weeding blade (Sweep) and cage wheel. The rated engine speed 3600 rpm was reduced to 23 rpm of the cage wheel by using chain and sprocket mechanism in three steps. Three ranges of approach angles 600, 700 and 800, forward speeds viz. 0.28 m/s, 0.42 m/s and 0.56m/s and moisture contents 13%, 15% and 18% were optimized on the basis of lowest specific draft and highest weeding efficiency. An approach angle of 70 degree at a forward speed of 0.42 m/s at 15% moisture contents of soil was optimized as it resulted in lowest specific draft as 0.619 N/mm and highest weeding efficiency as 89.58%. Further the weeder was evaluated at the optimized condition for cotton and redgram fields. The draft and weeding efficiency of developed self propelled weeder were found to be as 44 kg and 42.5 kg, 87.19 % and 84.19 % in cotton and redgram fields, respectively. Theoretical field capacity, effective field capacity and field efficiency were found to be 0.071 ha/hr and 0.072 ha/hr, 0.053 ha/hr and 0.055 ha/hr, 74.64% and 76.36 % in cotton and redgram fields, respectively. It was observed that operational cost of self propelled weeder was ` 1517.54/ha and 1476.54/ha for cotton and redgram respectively as compared to ` 2000/ha and ` 1980/ha for traditional method of weeding using hand khurpi. The saving in cost of 24.12 % and 25.42% were obtained for weeder as compared to traditional method in cotton and redgram.