Abstract <p>Pikeperch <i>Sander lucioperca</i> is a valuable fish species whose reproductive biology and efficiency of natural reproduction, as well as the factors determining them, are poorly studied. Based on the materials collected in 2018–2023, the results of the study of sexual maturation, gonadosomatic index (GSI), and absolute (AF) and relative fecundity (RF) of pikeperch from five areas of the Kama Reservoir, located on the northeastern border of the natural range of the species, are presented. The population fecundity of pikeperch and efficiency of species natural reproduction based on egg-to-adult survival coefficients are estimated. The latitudinal variability of pikeperch sexual maturity rates within the reservoir is revealed. A decrease in generative metabolism relative to somatic metabolism is found with the age of fish after they reached the length of 55–60 cm and 11+ age, which is manifested by the stabilization of the values of RF and GSI in larger and older fish. The maximum values of GSI, AF, and RF are observed for pikeperch in the lower part of the Kama Reservoir, which may be related to more favorable feeding conditions for the species. The lowest values of AF and RF are characteristic for the headwaters of the Kama Reservoir with highest water flow. At the same time, pikeperch in the upper part of the reservoir are characterized by the highest survival rate from eggs to adult individuals. The lowest efficiency of natural reproduction is found in the central part of the reservoir, characterized by maximum width, the presence of large bays, and the predominant distribution of shallow water habitats.</p>