This study presents an ARIMA model for forecasting the National Consumer Price Index (NCPI) in Nepal using annual data from 1972/73 to 2022/23. The research employs the Box-Jenkins methodology and E-Views software to identify the most suitable ARIMA model for NCPI forecasting. The ARIMA (1, 2, 8) model was selected as the best fit, validated through diagnostic tests that confirmed the residuals exhibited white noise characteristics. The model's accuracy was further supported by statistical measures such as Root Mean Squared Error (RMSE) and Theil Inequality Coefficient, which indicated a high level of precision in predicting NCPI trends. The findings suggest a continued upward trend in NCPI, with projections indicating an increase to around 200 by 2028. The study highlights the importance of NCPI as a key indicator of inflation and its implications for economic policy-making in Nepal. The ARIMA model provides a reliable tool for forecasting future price trends, aiding policymakers in making informed decisions regarding inflation control and economic stability. The research contributes to the field of economic forecasting by demonstrating the effectiveness of ARIMA modeling in capturing the dynamics of NCPI and its potential for future economic analysis and policy formulation.This study presents an ARIMA model for forecasting the National Consumer Price Index (NCPI) in Nepal using annual data from 1972/73 to 2022/23. The research employs the Box-Jenkins methodology and E-Views software to identify the most suitable ARIMA model for NCPI forecasting. The ARIMA (1, 2, 8) model was selected as the best fit, validated through diagnostic tests that confirmed the residuals exhibited white noise characteristics. The model's accuracy was further supported by statistical measures such as Root Mean Squared Error (RMSE) and Theil Inequality Coefficient, which indicated a high level of precision in predicting NCPI trends. The findings suggest a continued upward trend in NCPI, with projections indicating an increase to around 200 by 2028. The study highlights the importance of NCPI as a key indicator of inflation and its implications for economic policy-making in Nepal. The ARIMA model provides a reliable tool for forecasting future price trends, aiding policymakers in making informed decisions regarding inflation control and economic stability. The research contributes to the field of economic forecasting by demonstrating the effectiveness of ARIMA modeling in capturing the dynamics of NCPI and its potential for future economic analysis and policy formulation.