PURPOSE: To evaluate the utility of a telephone outcall program for cancer caregivers and to examine longitudinal changes in their distress levels and supportive care needs. METHODS: As part of the PROTECT trial, caregivers assigned to the intervention arm (N = 108) received three telephone outcalls from a Cancer Council 13 11 20 nurse at three time points (7-10 days post-randomization, 1 and 4 months later). During each call, caregivers were screened for distress using the Distress Thermometer (range: 0-10) then six supportive care issues were raised for discussion. Participants completed a utility survey 1 month post-intervention. RESULTS: The outcall program was highly acceptable and perceived as beneficial by caregivers. Overall, 95% reported it was worth their time to take part in the outcall program and 82% stated that the program was very relevant to them. Level of distress and impact of distress decreased over time (p = 0.0031, p < 0.0001, respectively). Average call duration decreased over time (p < 0.0001) and was longer for female than male caregivers (p = 0.0009). The frequency of caregivers discussing issues related to psychological distress (p = 0.0003), health literacy (p < 0.0001), financial (p = 0.0014), and practical concerns (p = 0.0121) decreased over time. Psychological distress was more often discussed by female than male caregivers (p = 0.0153), and family issues more often by younger (< 55 years) than older caregivers (p = 0.0071). CONCLUSIONS: Utility of this outcall program was high. Caregivers' level of distress and unmet needs decreased over time. Gender and age differences emerged, which warrants the need for tailored support. Further research is necessary to identify the best method of improving access to 13 11 20 services for caregivers.