Kutjevo wine-hills are located on southern slopes of Papuk and Krndija mountains. The area is the most famous by production of Graševina grapes, but increasing share of other varieties cannot be ignored. Chardonnay is the most widespread variety all over the world, and in Požeško-slavonska county is represented by 5 % of total vineyards area. The aim of this research was to determine the influence of cluster thinning in Kutjevo wine-hills on maturation and must quality of Chardonnay grapes. Research was conducted in 2020 in Podgorje location (Kutjevo wine-hills). Experiment was established by a randomized block schedule in two treatments with three repetitions. Five vines in a row makes one repetition. The following parameters have been determined: sugar content and total acidity in grapes in period of one month before harvest, number of clusters per vine, cluster mass, mass of 100 berries, density, total acidity, volatile acidity, tartaric acid, malic acid, lactic acid, pH, reducing sugars, extract, glucose, fructose, glycerol, alfa amino nitrogen, ammonia nitrogen and potassium. Results have showed that cluster thinning had a significant influence on cluster mass and number of clusters per vine, but majority of chemical parameters were not significantly different between two treatments. Statistically significant difference was only in case of pH, lactic acid and ammonium nitrogen Vinogorje Kutjevo smješteno na južnim obroncima Papuka i Krndije najpoznatije je po uzgoju grožđa Graševina, međutim ne smije se zanemariti i sve veća zastupljenost ostalih sorti. Chardonnay je najraširenija vinska sorta u svijetu, a u Požeško-slavonskoj županiji zauzima oko 5 % površine vinogradarskih nasada. Cilj ovog rada bio je odrediti utjecaj prorjeđivanja grozdova u vinogorju Kutjevo na kinetiku dozrijevanja grozdova, te kakvoću mošta kultivara Chardonnay. Istraživanje je provedeno tijekom 2020. godine na lokalitetu Podgorje (vinogorje Kutjevo), a pokus je postavljen po slučajnom bloknom rasporedu u dva tretiranja po tri repeticije. Repeticiju čini pet trsova u nizu. Ispitivani su sljedeći parametri: udio šećera i ukupna kiselost u grožđu u periodu mjesec dana prije berbe, broj grozdova po trsu, prosječna masa grozdova, te masa 100 bobica. U moštu su određeni sljedeći parametri: gustoća, ukupna kiselost, hlapiva kiselost, vinska, jabučna i mliječna kiselina, pH, reducirajući šećeri, ekstrakt, glukoza, fruktoza, glicerol, alfa amino dušik, amonijačni dušik, te kalij. Prorjeđivanje grozdova je statistički značajno utjecalo na broj grozdova, masu grozdova, pH vrijednost, mliječnu kiselinu i amonijačni dušik, dok kod drugih analiziranih parametara nije bilo statistički značajne razlike između pokusnih varijanata