The present analysis of sexual allometry is based on the study of 26 adult specimens (12 females and 14 males) of pikeperch (Sander lucioperca) from the same lake. On their left lateral aspect, 19 homologous landmarks were obtained which were studied according to geometric morphometric methods. The utilization of geometric morphometric techniques in assessing allometry in the present study showed that size only accounted for a 4.4% of the shape and that it did not appear allometric relationships neither for males nor for females for the selected most discriminative landmarks. These results may be useful for comparing allometric patterns of pikeperch between geographical populations or ecological variants, fitness, fish movements, spatial scales, and for studying the body size dependence of energy storage and size-related biokinetics.