The first objective of this study was to compare quantitative trait loci (QTL) detection in two climatically diverse environments in a population of F6:7 lines of an elite maize (Zea mays L.) single-cross. The second objective was to detect QTL for general (GCA) and specific (SCA) combining ability effects in hybrid progeny of F2:3 and F6:8 lines from the same population. Evaluations of both inbred per se and hybrid progeny from the same population enabled comparisons between QTL controlling the two progeny types;The results from the F6:7 inbred progeny evaluations suggest that QTL detection can be greatly affected by environmental conditions with only 17% (grain yield traits) and 35% (morphological traits) of the QTL detected among the stress and nonstress environments being detected in both environments. The mean environment was effective in detecting 68% (morphological traits) and 54% (grain yield traits) of the QTL detected in either of the individual environments. A comparison with the mean environment (same location, different years) results for the F2:3 generation of the same population revealed that 50% of the morphological trait and 33% of the grain yield trait F2:3 QTL were verified in the F6:7 mean environment. Little evidence of cross-over QTL interaction was observed, and QTL x environment interactions seem to be in the form of changes in magnitude of effects;The hybrid progeny from the two generations (F2:3, F6:8) were evaluated at the same locations, but in different years as per an early-generation testing program. Overall, more QTL were detected in the F6:8 than the F2:3 generation for SCA and GCA. The morphological traits had several (8-11) QTL with effects for all three testers, whereas only one GY QTL had effects for all three testers. Of 26 regions having consistent morphological trait QTL effects in the inbred progeny, most (20) were also associated with GCA, whereas a lower proportion (five of ten) of the consistent inbred progeny grain yield QTL were also associated with GCA. Although the relative rankings of QTL effects across generations, testers, and progeny types were not always consistent, parental contributions were nearly always the same.