This thesis is an investigation of selecting markers on chromosome 7 within the SLA region and identifying the existence of polymorphisms in each population set with respect to the markers selected. If a polymorphism was found, a comparison was made of the different genotypes (banding patterns) to determine association with high and low levels of androstenone. Results of this study clearly associated polymorphisms in markers Bf, BAT1, CYP21, TNF[alpha], S0064, SW1344 and SW2019, located within the expected QTL region for androstenone level on porcine chromosome 7, associated with androstenone levels. No significant associations were found between the genotypic distribution of high and low androstenone categories for all breed groups investigated. Significant associations were found between the number of copies of particular alleles and fat and plasma androstenone levels. Genes BAT1, TNF[alpha], CYP21 and microsatellites S0064 and SW2019 appear to be associated with the genetic control of androstenone.