The purpose of this work was to prepare already collected data for further statistical testing of the scientific hypothesis that can be set with respect to biometric data (weight, length) and related to (allometry and condition index). The aim of this work was the digitalization, systematization and presentation of original field biometric parameters of Mytilus galloprovincialis specimen from natural mussel populations collected from 2000 to 2010 in March, June, August and October, along the eastern coast of the Adriatic Sea at 24 locations. Allometry distinguishes three growth types: isometric growth when the growth in length is accompanied by weight gain, positive allometric growth when the weight increase is greater than the increase in length and negative allometric growth when the increase in length is greater than the weight increase. The condition index represents the ratio between soft tissue content compared to the total weight and is a reflection of the environmental conditions. The original field data were digitalized in the Excel computer program where two data sets were created. The first set contains data for 3422 specimens for determination of allometric growth equation, calculated using regression analysis. The isometry was determined after testing the equation slope using a network service. The growth throughout the year was determined for 16 stations as follows: 13 have negative allometric growth, 2 populations are isometric while one express positive allometric growth. Allometric vector W =0.0005L2.610 (R2 = 0.878) obtained from all population data indicated negative allometry of the natural mussel populations of M. galloprovincialis on the eastern Adriatic coast. The second set contained data for 2298 specimens for condition index determination. The condition indices were determined seasonally for 18 sampling sites. The majority of sampling sites (12) have the lowest condition index in March, highest in October (10) and August (7), while at one location the lowest condition index was in August and the highest in March. The results of this work would serve as a starting point for testing the scientific hypothesis that can be established with respect to biometric data (weight, length) and related to mussel growth according to cubic law and environmental conditions represented by condition index.