[full article and abstract in Lithuanian; abstract in English] The sports results of boxers and their success depend on a number of factors, but mostly on the effectiveness of sports training. The continual practice process is a rather complex system that can be managed using a variety of types, forms, tools and methods of control. However, the main attention in box is paid on the physical capacity of athletes related to the movement capabilities, since the boxing results in competitions essentially depends on it. There is not so much of scientific research on the physical capacity of boxers; therefore, it was relevant to analyze the peculiarities of physical preparation of adult boxers in this article as well as to study their physical capacity. The object of the research is the physical capacity of adult boxers of Klaipėda Boxing Club “Cempionas”. The aim of the research is to study the physical capacity of adult boxers of Klaipėda Boxing Club “Cempionas”. Research objectives: 1. To study the physical capacity of adult boxers of Klaipėda Boxing Club “Cempionas”. 2. To compare the results of physical capacity of athletes of Klaipėda Boxing Club “Cempionas” with the reference scores of residents Lithuania. The research methods were theoretical (analysis of scientific literature), empirical (testing) and statistical analysis of data. The research was conducted in February – April, 2018 in the sports hall of Klaipėda Boxing Club “Cempionas” and Klaipėda City Central Stadium. In order to study the physical capacity of adult boxers, the following research methods were used: analysis of scientific literature, testing and mathematical statistics. The 44 boxers of Klaipėda Boxing Club “Cempionas” have volunteered to participate in the research. The following tests on physical capacity have been performed to assess the respondents: sit and lie, crossbar pull-ups, sit and seek, hand grip, standing long jump, flamingo balance test, hand bending and stretching in a lying position, shuttle run – 10 × 5 meter, 3 km run. After examining the physical capacity of the adult boxers of Klaipėda Boxing Club “Cempionas”, it was determined that the average score for the “sit and lie” test was 35.8 ± 3.64 times; the average score of the crossbar pull-ups test was 19.5 ± 3.34 times; the average score of the test for hand-bending and stretching was 91.4 ± 18.55 times; 3 km running – 13 min 54 s ± 1 min 3 s; “sit and seek” – 27 ± 5.83 cm; the average score for the right and left hand grip, respectively 57.5 ± 5.7 and 56.2 ± 4.33 kg; standing long jump – 263.2 ± 17.76 cm; the average score of “Flamingo test” was 0.6 ± 0.58 times. Comparing the results of the physical capacity of the boxers with the reference scales of the physical capacity of the Lithuanian residents, it was found that the boxers statistically significantly performed more sit-ups from the lying position during 30 s, more crossbar pull-ups, push-ups, they were more agile and had a better balance (p 0.05). Keywords: boxers, men, physical capacity. DOI: https://doi.org/10.15823/sm.2019.95.6