There is limited information on how residential property prices will evolve in the long term in Poland. Knowledge of this subject is crucial not only for policymakers but also for private individuals. Accordingly, this study aims to forecast long-term real residential property prices in 17 Polish provincial capitals. Using data on real housing prices in the primary and secondary markets from 2006 to 2025, four forecasting approaches were tested: ARIMA (autoregressive integrated moving average), ARIMAX (autoregressive integrated moving average with exogenous inputs), UCM (unobserved components model) and LSTM (long short-term memory). The forecast of residential property prices through the end of 2035 showed that price increases will be observed across all cities, though they will be highly heterogeneous. Significant growth is expected in large metropolitan areas, while in smaller provincial cities prices will rise only slightly due to a projected population decline. But if the demographic outlook turns negative, prices will fall across almost all the markets analysed.