Objectives The purpose of this study was to explore relations among thriving, cognitive function, and neuropsychiatric symptoms (NPS) in nursing home residents. Methods A national, cross‐sectional, randomized study of Swedish nursing home residents (N = 4831) was conducted between November 2013 and September 2014. Activities of daily life functioning, cognitive functioning, NPS, and thriving were assessed with the Katz activities of daily living, Gottfries' Cognitive Scale, Nursing Home version of the Neuropsychiatric Inventory, and Thriving of Older People Scale, respectively. Individual NPS were explored in relation to cognitive function. Simple linear and multiple regression models were used to explore thriving in relation to resident characteristics. Results Aggression and depressive symptoms were identified as negatively associated with thriving regardless of resident cognitive functioning. At higher levels of cognitive functioning, several factors showed associations with thriving; however, at lower levels of cognitive functioning, only the degree of cognitive impairment and the NPS was associated with thriving. Most of the individual NPS formed nonlinear relationships with cognitive functioning with higher symptom scores in the middle stages of cognitive functioning. Exceptions were elation/euphoria and apathy, which increased linearly with severity of cognitive impairment. Conclusions The lower the cognitive functioning was, the fewer factors were associated with thriving. Aggression and depressive symptoms may indicate lower levels of thriving; thus, targeting these symptoms should be a priority in nursing homes. Copyright © 2017 John Wiley & Sons, Ltd.