Among all the insect pests, brown planthopper (BPH), Nilaparvata lugens (Stal) (Homoptera: Delphacidae) is one of the most destructive pests of rice causing severe yield losses. In this study, an attempt was made to map QTL associated with resistance to BPH using a RIL (F7) population derived from the cross Swarna/PTB33 using standard seedling seedbox screening technique (SSST) at seedling stage, modified mass tiller screening (MMTS) at tillering stage and field screening (FS) at vegetative and reproductive stages in three replications. The mean damage score values of mapping population evaluated for BPH resistance in SSST (score 4.4), MMTS (score 4.1) and FS (score 4.6) methods were showed significantly higher resistance than the recipient parent Swarna (Score 9). Out of 327 SSR markers, 105 markers revealed polymorphism between the parents. QTL analysis detected 4 major QTL on chromosomes 1, 6 and 12 and 2 minor QTL on chromosome 3 and 6 derived from PTB33. Among 4 QTL detected QBph6.1 (RM7158-RM19606), QBph6.3 (RM402-RM276) and QBph12.1 (RM28378-RM28427) were associated with high phenotypic variance and tightly linked markers which enable their practical utility in marker assisted selection. The results indicate phenotypic analysis at sensitive stage (maximum tillering to soft dough stage) of crop growth for BPH resistance would help in improving the efficiency of QTL detection and efficient introgression of these QTL’s into elite rice cultivars, an important approach to develop stable resistance to BPH and in understanding the quantitative resistance to BPH in rice.