Abstract: The objectives of this study were to determine the genetic variability (σ2G) and thereby estimate the genetic gain after two cycles of selection within two sweet corn source populations, BC1-10xSyn-II and BC2-10. Selfed progenies from each of the two source populations were evaluated following the recommended cultural practices. As the progenies derived from the two source populations had sufficient genetic variability for most traits, two cycles of mass selection (MS) and selfed progeny selection (SPS) were conducted on the two sweet corn populations (BC2-10 and BC1-10xSyn-II). The two base populations showed varied average realized responses to MS and SPS. In BC2-10 derived populations, the realized responses to MS were 5.1% in cycle 1 (C1) and 4.8% in Cycle 2 (C2), whereas the realized responses to SPS were 9.1% in C1 and 1.2% in C2. In BC1-10xSyn-II derived populations, the realized responses to MS were 5.5% in C1 and 2.9% in C2, while the realized responses to SPS were 5.6% in C1 and 2.9% in C2. The two selection methods were equally effective in improving the populations for ear length, except in C1 of BC2-10, where SPS was more effective than MS. Both selection methods were also effective in increasing fresh ear yield and number of kernels per row. Response of other correlated traits depended on selection methods used and populations under selection. The improved populations generated could serve as better germplasm sources and further selection in these populations could offer better responses.