Older people's sleep and associated health implications loom large in aging societies. Self-determination theory indicates lagged or immediate interplays between subjective sleep and satisfaction of basic psychological needs (for autonomy, relatedness, and competence). However, little is known about their longitudinal dynamics in later life.This study investigated longitudinal reciprocities between satisfaction of basic psychological needs and subjective sleep for older people and controlled for six sociodemographic and health-related covariates.Three waves of data from the Chinese Longitudinal Healthy Longevity Survey (2011, 2014, and 2017) were analyzed using Structural Equation Modelling (N = 2,834, 52.68% women, Mean age = 78.36). Participants reported sleep quality and duration, satisfaction of basic psychological needs, and sociodemographic and health characteristics. Four competing models were examined: Model A conceptualized lagged effects of sleep on need satisfaction and vice versa (i.e. cross-lagged design), Model B described immediate needs' effects on sleep but lagged opposite effects, Model C reversed Model B's specifications, and Model D portrayed concurrent feedback loops.It was found that satisfaction of psychological needs and sleep quality declined over the seven-year span, but sleep length only fluctuated trivially. All models fitted the data well, where better sleep quality consistently predicted higher levels of need satisfaction, especially for relatedness and competence. Sleep interacted most robustly with relatedness: Models A, B, and C revealed positive lagged or immediate reciprocities between sleep quality and relatedness, and Model D yielded negative feedback loops between sleep length and relatedness.The study identified longitudinal immediate or lagged interplays between need satisfaction and sleep for older people, especially concerning relatedness need. Implementation of need-supportive interventions and promotion of healthy sleep habits are necessary for healthy aging.