Background: Non-CNS cancer and treatments are associated with neurocognitive sequelae in older adults; whether YAC (age 18-39 yrs) are protected from these effects is unknown. In YAC, cancer interferes with education and occupational attainment and is associated with psychological distress. This prospective, inception-cohort study characterizes neurocognitive functions and psychological distress in YAC. Methods: YAC completed a 2-hr battery of standardized neurocognitive tests and questionnaires 1.7 ± 1 months after diagnosis prior to chemotherapy (mean ± SD, T1) and 8.2 ± 1.2 (T2) and 14.2 ± 1.6 (T3) months later. Healthy YA with no cancer history (HYA) were tested at similar time points. Tests were scored using published norms, transformed to T-scores, and grouped into neurocognitive domains. Results: YAC (n = 108; lymphoma, breast, gyne, GI, GU, sarcoma) were grouped according to whether they required chemotherapy (n = 70) or not (n = 38), and compared to 63 HYA. At baseline, there were no group differences in neurocognitive performance, number of impaired tests, or neurocognitive complaints (Kruskal Wallis, all p-values > .4). About 70% of each group completed assessments at T2 and T3. Mean performance improved over time (random effects models, all p-values < .01), but there were no group differences or interactions between group and time. There were also no differences in proportions of participants in each group whose test scores improved ( > 10 points) or declined ( < 10 points) from T1 to T2 or T3. Adjusting for psychological distress, fatigue, or neurocognitive complaints did not change these results, despite higher symptoms of somatic distress, anxiety and fatigue in YAC compared to healthy YA over time (all p-values < .03). Conclusions: Before chemotherapy and up to about 14 months later, YAC have elevated distress and fatigue, but do not demonstrate the cognitive decline reported in older cancer patients. Our findings are consistent with research suggesting that aging brains are more vulnerable to neurotoxic insult. Whether the effects of cancer treatment emerge later in YAC, placing them at risk for accelerated aging as reported in older patients, remains to be examined.