This study assessed the current condition of Castanea sativa Mill. (European chestnut, Fagaceae) stands in the foothill villages, private holdings and natural foothill forests of the Sheki-Zagatala region of Azerbaijan, at altitudes of 600–1,600 m above sea level, following three decades of decline attributed to chestnut blight (Cryphonectria parasitica (Murrill) Barr) and root and collar rot (Phytophthora spp.). Field expeditions were conducted over two consecutive seasons across 71 villages in seven administrative districts — Balakan, Zagatala, Gakh, Sheki, Oguz, Qabala and Ismayilli — and stand density was assessed following the methodology of Nesterov (1954). Across the surveyed area, approximately 65% of chestnut plants had died as a result of disease, while a further 30% of the surviving plants were infected and undergoing progressive dieback. Severe desiccation affecting 60–65% of the stand was recorded in 54 villages, whereas chestnut stands had been eliminated entirely in 17 villages. Disease severity was consistently greater in villages along the southern margin of the region than in the foothills. Trees older than 50–100 years, which formerly accounted for the largest share of production, were infected at the earliest stage and were the first to die; regional chestnut yield has consequently fallen by 60–70% relative to the 1990s. Field observations further demonstrate that C. parasitica alone does not account for the mortality observed: root and collar rot caused by Phytophthora was recorded in numerous dead trees, and in some dead trees stem canker was absent entirely. A combined phytopathological approach is therefore required for any restoration programme.