The aim of this study was to assess the anthropometrical data and physical fitness of soldiers according to the sociodemographic characteristics during one-year compulsory military service. The height and weight of 197 soldiers were measured at the beginning and at the end of their service, and body mass index was calculated. The physical fitness was evaluated using index of ability on the basis of 2 km walking test. Conscripts from cities were taller than conscripts from rural areas. At the beginning of the service every fifth was overweight (25< or = body mass index <30 kg/m2) or obese (body mass index > or =30 kg/m2): 17.9% of conscripts from rural areas as well as 17.6% from urban were overweight and 1.9% from rural as well as 1.1% from urban areas were obese. A tendency that the weight of conscripts gradually increased with the level of education was observed. There were no significant differences in index of ability according to the level of soldiers' education as well as place of residence. During one-year service the height of soldiers did not change, however, their weight increased in average by 5.5+/-4.5 kg (p<0.01). The part of overweight persons at the end of the service increased 2.3-fold. Physical fitness of soldiers after one-year service significantly decreased compared with the beginning of the service. In order to decrease the rate of overweight soldiers and to increase their physical fitness the health promotion programs in Lithuanian Army are needed.