This paper is focused on the study of the performance constituent variability in 104 new winter bread wheat cultivars from 10 countries worldwide, which was carried out in 2016-2019 at the Plant Production Institute named after V.Ya. Yuriev of NAAS of Ukraine. Research results revealed that spike length was the least variable parameter depending on the growing conditions (CV = 2.0–19.2%) and that the following characteristics responded most strongly to changes in the growing conditions: kernel number per spike (CV = 3.5–30.6%), spike weight (CV = 2.3–47.1%), and kernel weight per spike (CV = 1.2–55.1%). According to the variability degree, it was established that cv. Ladyzhynka, Polianka, and Apertus were most responsive to changes in the growing conditions, while cv. Dobirna, Darynka Kyivska, MIP Asol, and Cappelle Desprez were stable in terms of expression of the performance constituents and yield.