Proper planting density and weeding playan important role on proper growth, productivity and quality of crops. The present study was undertaken to evaluate effect of inter row spacing and weeding frequency for their phenologycal parameter, yield and yield component and quality parameter at Gambella University College of Agriculture and natural resource, South West Ethiopia. Four level of inter row spacing and four level of weeding frequency were evaluated in randomized complete block design with three replication. The interaction effect of inter row spacing and weeding frequency showed significant variation both phenologycal performance yield and yield component as well as quality parameter. Among the treatment tested a combination of 70x10cm spacing with three times weeding registered 49.867cm of plant height. Early flowering 31.883 days maturity 136.693 days and high LAI 4.546 were observed on treatment combination of 40x10cm and zero weeding. In terms of yield and yield component, higher number of pod per plant 45.003, dry pod yield 2909.47 kg/h and seed yield 2360.15kg/ha were observed on 60x10spacing with two times weeding treatment combination. On the other hand, highest harvest index 28.41% was observed from three times weeding frequency. However, number of seed per pod shows none significant effect. Furthermore, interims of quality parameter oil content 32.483% were observed on three times weeding frequency and highest protein content 20.816% and 19.2833% were observed from three times weeding frequency and 70x10cm spacing respectively. Generally according to the result of the study spacing of 60x10cm with twice weeding at 10 days interval can be recommended for groundnut production in Gambella. However, this is one time and one location experiment therefore it should have to be repeated in different location and season to get reliable result.