We studied the reproductive, nesting, and hatchling ecology of the endangered Alabama red-bellied cooter (Pseudemys alabamensis) from 1997 to 2001 and in 2003 in the Mobile–Tensaw Delta, Alabama, USA. Nesting activity peaked in June and July and mean clutch size was 13 eggs (n = 31), with a strong positive correlation between clutch size and female carapace length. Females may lay multiple clutches in single- or multiple-chambered nests; adult and juvenile females dig false nests. Nonoverwintering hatchlings had a development period of 101 days (n = 21 nests); overwintered hatchlings emerged beginning in March of the next year. Mean hatchlings weight was 11.7 g with a carapace length of 39.1 mm (n = 262). We tested a headstart program on 6 hatchlings raised in captivity for 16 months and released as large, juvenile turtles; results suggest that the headstart program is a feasible approach to increase juvenile survivorship. We propose the following plan to prevent further population declines: 1) construction of a permanent barrier to prevent nesting females and hatchlings from being killed by vehicular traffic on the Causeway (US 90/98), 2) limitation of disturbance to nesting habitat in the Mobile–Tensaw Delta, and 3) initiation and evaluation of a 1-year headstart program to increase recruitment.