In this paper we examine the utility of the Bayesian model averaging approach proposed by Blangero et al. [Genet Epidemiol 17(Suppl. 1):S67-72, 1999] for the detection of known oligogenic effects on quantitative trait 1 (Q1) in the simulated Genetic Analysis Workshop 12 data. The results were consistent with the underlying genetic model: two major QTLs were identified on chromosomes 19 and 2, with heritabilities of 17% and 20%, respectively, located near the position of major genes 1 and 2.