The post-war settlement of part of the territory of the former East Prussia is one of the most important events in the history of the newly formed region, which was reflected in a key way at all stages of its formation as part of the RSFSR. The scale of the migration process makes it one of the largest organized by the Soviet government. In the article, based on the statistical analysis of the database currently being filled in, "Echelon lists of migrants to the Kaliningrad region. 1946-1947" and studies of the texts of memoirs of the first settlers collected in the 1980s and 90s, the sex and age composition of the first and most numerous migration wave is characterized. It was found that mainly families of 4-6 people were resettled, headed by a 40-year-old man. At the same time, there were 1.6 times more women among those over the age of 18. Two thirds of the arrivals were minors, the average age of which is 10 years. Despite the fact that the memories of the resettlement participants were recorded at a much later time, they are consistent with the statistical estimates obtained. The results of the work partially fill in the information that has been missing so far about the exact composition of the Kaliningrad migration, which, as can be seen, is significantly younger, and therefore more balanced in terms of sex ratio than the population of other regions of the Soviet Union.