ABSTRACT.- Pears are widely cultivated in the world. Uruguayan production covers 628 ha. Practically, in its entirety, European-type pear trees (Pyrus communis L.) are grown, and the most planted cultivar is Williams. Most of the orchards in Uruguay are managed without the use of pollinating cultivars. Pear production in recent years has not been stable, with the lack of pollinators one of the main factors that could be influencing this. The aim of this study was to evaluate the phenology and the potential of different pear cultivars to increase fruit set in the climatic conditions of Uruguay. The study was carried out during the 2020/2021 and 2021/2022 growing seasons in pear orchards at "Instituto Nacional de Investigación Agropecuaria", Canelones, Uruguay. 'Williams' and 'Early Bon Chretien' pears were used as main cultivars. Treatments consisted of different pollen sources, in addition to spontaneous self-pollination, forced self-pollination and emasculation. Controlled pollinations were carried out between 10 September and 20 October, and 15 September and 4 October in the 2020/2021 and 2021/2022 growing seasons, respectively. The flowering period in 2021/2022 was shorter than in 2020/2021, where some cultivars presented a decrease in the bloom period of 10 days or more. Generally, in both growing seasons all pollen sources increased fruit set of 'Williams' and 'Early Bon Chretien' pears compared to unpollinated or self-pollinated treatments. Collectively, with the results of both seasons, the pollinizers 'Santa Maria' and 'Devoe' were the most efficient in increasing fruit set of 'Williams' pears, while for 'Early Bon Chretien' the best pollinizers were 'Forelle', 'Abate Fétel' and Pyrus calleryana. © 2024 International Society for Horticultural Science. All rights reserved.