Field experiment on economics and productivity of sunflower with response to spacing and weed management practices was conducted at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, during rainy season of (Kharif) 2016 and 2017 with objective of checking the suitability of spacing for moment of power weeder. Experiment was laid out in strip plot design and replicated thrice. The treatment comprised of five horizontal factors as plant spacing and five vertical factors as weed management practices. The higher cost of cultivation was registered with spacing 90 × 15 cm among different spacing and increased in gross returns, net returns, B:C ratio, per day return and seed yield with the spacing 75 × 25 cm. Hand weeding twice at 15 and 30 DAS recorded the higher cost of cultivation, gross returns, per day returns and seed yield among the different weed management practices during the both years of experimentation. Results of two year experimentation revealed that increased in net returns with pendimethalin at 1 kg/ha followed by hand weeding at 30 DAS and higher B:C ratio was recorded with pendimethalin at 1 kg/ha followed by weeder at 30 DAS.