The assessment in 13 rice genotypes that consisted of MR219, Mahsuri Mutant, Basmati 370, MRQ76, MRQ74, MRQ50, and Mahsuri Mutant 98 as parental lines, and six rice combinations were conducted in MARDI Seberang Perai, Penang. This assessment analyzed the variability among parental lines and F1 generations, including heterosis mechanism in rice combinations for the identification of better traits related to grain quality and yield. The parental lines, Basmati 370, MRQ50, MRQ74, MR219 and Mahsuri Mutan have long and slender grains. This characteristic is desired in breeding for grain quality traits. It was found that cross Basmati 370 × MR219 showed the best performances in most of the grain quality traits with grain shape >3 mm. Besides that, it also showed significant differences as compared to other. The findings included that the cross had the highest value in plant height (120.2 cm), panicle length (30.4 cm), thousand grain weight (26 g), and flag leaves length (42.4 cm). Pearson correlation analysis showed that strong positive relationship and a significant association were found between traits panicle fertility and tiller number (0.843), and traits milled grain length and length/breadth ratio (0.768). Heterosis analysis showed that RU14387 posed positive heterosis value in most of the traits studied except for the panicle fertility and filled grain per panicle traits when compared with better parent. RU14387 also recorded positive heterosis over standard check variety in length/breadth ratio and milled grain length compared to standard check variety. The information gained from this study can be a great foundation for future rice development study of rice lines with better grain quality and high yield.