The Prolonged drought resulting from global warming is considered an important factor affecting the Asia's socioeconomic growth of West Asia, with a significant impact on the dynamic forecasting of water supply and forest ecosystems. In such a scenario, Understanding future long-term drought (SPEI) changes is crucial for accurately forecasting regional drought shifts in the Hindukush region. In this study, a 517-year (1506-2022 CE) long tree-ring width chronology of the Himalayan Cedar (Cedrus deodara D. Don) from the eastern Hindukush has been developed. The July-September SPEI has revealed a positive and significant relationship (r = 0.633, p < 0.001) with tree growth, which leads to SPEI reconstruction from AD 1626 in the Hindu Kush Region. Our reconstruction model has explained 40.01% of the climate variance during the instrumental period from AD 1965 to 2018. Fourteen wet periods (β₯ 3 years) were observed before the instrumental period, specifically in C.E. 1629β1635, 1638β1658, 1666β1674, 1680β1701, 1715β1724, 1770β1776, 1794β1797, 1802β1810, 1822β1846, 1850β1857, 1872β1881, 1883β1890, 1906β1914, and 1921β1937. Similarly, twelve dry summer periods were also observed in the past 339 years, such as C.E. 1659β1665, 1675β1679, 1702β1714, 1725β1769, 1777β1793, 1798β1801, 1811β1821, 1847β1849, 1858β1871, 1891β1905, 1915β1920, and 1938β1963. Nevertheless, AD 1663 was individually the wettest (with a value of 2.13), while AD 1754 was the driest (-0.99) year. The spatial correlation analysis and its comparisons with Karakoram-Himalayan drought and precipitation reconstructions have convincingly confirmed the reliability of our SPEI reconstruction. Consequently, this reconstruction can effectively serve as a proxy for large-scale drought variability in the Hindu Kush region of northern Pakistan. Our findings strongly suggest the considerable dendrochronological potential for further climatological studies in the western Hindu Kush Mountains System.