Litter size is a complex and sex limited trait that depends on various biological, managemental and environmental factors. Owing to its low heritability it is ine caciously selected by traditional methods. However, due to higher heritability of ovulation rate and embryo survival, selection based on component traits of litter size is advocated. QTL analysis and candidate gene approach are among the various supplementary/alternate strategies for selection of litter size. QTL analysis is aimed at identifying genomic regions affecting trait of interest signi cantly. Candidate gene approach necessitates identi cation of genes potentially affecting the trait. There are various genes that signi cantly affect litter size and its component traits viz. ESR, LEP, BF, IGFBP, RBP4, PRLR, CTNNAL1, WNT10B, TCF12, DAZ, and RNF4. These genes affect litter size in a complex interacting manner. Lately, genome wide association study (GWAS) have been utilized to unveil the genetic and biological background of litter traits, and elucidate the genes governing litter size. Favorable SNPs in these genes have been identi ed and offers a scope for inclusion in selection programs thereby increasing breeding e ciency and pro t in pigs.