Broad-leaved weed in chickpea is one of the most important obstacles to product chickpea. Thus, in order to determine the best time of herbicide application and plant density to decrease weed population and increase yield of chickpea a field experiment was carried out at Naveh kesh Agricultural Jihad Center in Khorramabad, Iran on March 15, 2014. The experiment was carried out as split-plot based on randomized complete block design with four replications. Weed control was imposed at four levels – Lentagran herbicide application (15, 30 and 45 days after emergence) and control – as the main plot. Plant density was adopted at three row spaces – 20, 30 and 40 cm with 10 cm on-row spacing – as the sub plot. The results showed that plant density and Lentagran herbicide application significantly affected grain yield, weed weight and weed number. The highest and lowest grain yields were obtained by 30 and 40 cm row spacing respectively. Lentagran herbicide application at 30 days after emergence had the highest grain yield. The highest weed weight and weed number were shown in row spacing of 40 cm. The best combination treatments were found by row spacing of 30 cm and Lentagran herbicide application at 30 days after emergence, so that they could have the highest grain yield and lowest weed weight and weed number.