Common and Tifton 44 bermudagrass [Cynodon dactylon (L.) Pers.] located at Fayetteville and Batesville, AR, respectively, were chosen during 2000 and 2001 to evaluate the effects of stockpiling initiation date (August or September) and N fertilization rate (0, 37, 74, or 111 kg N/ha) on the nutritive value of stockpiled bermudagrass forage. Harvest dates began in mid-October and continued at three-wk intervals through December. At Fayetteville, there were initiation x harvest date interactions for NDF (P = 0.057), ADF (P = 0.003), hemicellulose (P = 0.003), cellulose (P = 0.001), lignin (P = 0.007), and crude protein (P = 0.008) during 2000, and strong interactions (P < 0.001) for all response variables in 2001. Generally, NDF, ADF, cellulose, and lignin increased over harvest dates for both initiation dates in 2000, and for the August initiation date in 2001. However, concentrations of fiber components for stockpiled forages initiated in September 2001 declined over harvest dates because of contamination by winter-annual species. At the Batesville site, a N fertilization effect (P < 0.017) was observed for NDF and ADF for both 2000 and 2001, and for cellulose (P = 0.001) in 2001. Initiation date had no effect (P > 0.05) on the concentration of any fiber component in 2000, but affected (P < 0.027) all fiber components in 2001. In contrast, harvest date affected (P < 0.001) concentrations of all fiber components during both years. Crude protein increased (P < 0.001) with N fertilization rate during both harvest years, while the initiation x harvest date interaction and the main effect of initiation date were significant (P < 0.009) during 2000 and 2001, respectively. Generally, the nutritive value of stockpiled bermudagrass declined between mid-October and late December, unless late-summer fertilization with N encouraged growth of other contaminant grass and broadleaf species.