<p>Pistachio orchard expansion in semi-arid environments requires careful site selection because climatic suitability, soil conditions, topography, accessibility and land-use restrictions vary considerably across space. This study assessed the land suitability of Batman Province, southeastern Türkiye, for pistachio cultivation by integrating Geographic Information Systems and the Pythagorean fuzzy SWARA method. Fifteen preference criteria were evaluated under four groups: meteorological, soil, topographic and infrastructural-economic factors. Sixteen exclusion factors were also used to remove areas with legal, environmental or technical limitations before suitability modelling. Expert evaluations from local pistachio producers and agricultural specialists were converted into Pythagorean fuzzy numbers to account for uncertainty and hesitation in criterion weighting. The weighted criteria were integrated using a GIS-based weighted overlay procedure. Annual average temperature, critical period mean minimum temperature and land use capability class were the most influential factors in the model. After exclusion masking, 19.03% of Batman Province was classified as very highly suitable and 27.10% as highly suitable for pistachio cultivation. Model performance was assessed using existing pistachio orchard locations and receiver operating characteristic analysis. The AUC value was 0.916, indicating strong spatial agreement between the suitability map and current orchard distribution. The study addresses the lack of a crop-specific, uncertainty-aware pistachio suitability framework for Batman Province and provides a reproducible decision-support approach for guiding orchard planning in semi-arid agricultural landscapes.</p>