Roundup ReadyŽ corn (Zea mays L.) hybrids offer potential for use as silage to support the dairy industry in Puerto Rico. This study assessed silage yield, fermentation characteristics, and aerobic stability of two Delkab corn hybrids (DKC 67-60 and DKC 69-71). Corn hybrids were drilled on well prepared seed-beds previously planted to signalgrass (Brachiaria decumbens). Soil type was a Fraternidad series (Fine, smectitic, isohypothermic Typic Hapluderts). First planting occured in May, 2004 and a second planting in September, 2005. The design was a completely randomized block with four replicates. At dough stage (90-d post planting), a 2 m² area of planted corn was harvested; chopped-finely and ensiled in micro-silos (1.8 kg capacity). Sub-samples (500g) were taken for nutritive value analysis. After 45-d of ensiling, silage was analyzed for pH and fermentation products. Stability of the resulting silage was determined during 7 days of aerobic exposure. Silage yield did not differ (P>0.05) among hybrids (14.4 and 13.7 Mg ha^-1 for DKC 67-60 and DKC 69-71, respectively). Crude protein was low for both hybrids (ave. 4.8%) and NDF was similar for DKC 67-60 (56.8%) and DKC 69-71 (57.7%). Final pH was lower (P<0.05); 3.63 vs. 3.85) in DKC 69-71 compared to DKC 67-60, but fermentation end products were similar. As expected, aerobic instability increased as time of aerobic exposures increased. These results show that both hybrids have potential for use in the Caribbean basin, but are dependent on adequate rainfall.