The biometric relationships between different body measures (in length) and body weight of the giant red shrimp, Aristaeomorpha foliacea, from the Strait of Sicily (Central Mediterranean Sea) were analysed. A maximum likelihood index of goodness of fitting (Furnival´s index) was used to compare the performance of the models. Fresh and thawed measures were also compared, the latter being significantly different from the former. Total and ocular length and length-weight relationships resulted significantly negative allometric (b <1 or b <3, respectively) in both sexes. Length relationships in males showed discontinuities as a consequence of their rostrum shortening process. The estimated coefficients in the morphometric relationship for females were used to compare standard (based on carapace length) and other (based on different body measures) length frequency distributions derived from older literature. The length-weight relationship for A. foliacea females of the Strait of Sicily appeared very similar to those derived for other conspecific populations, but quite different (higher weight for the same length) in respect to the similar species Aristeus antennatus.