After the occupation of the Kingdom of Yugoslavia and the proclamation of the Independent State of Croatia, the first partisan units were formed on the territory of Croatia under the leadership of the Communist Party of Yugoslavia. Due to the specifics of the war in Croatia, there was a mass enlistment in the partisans. Such massiveness manifested itself in great needs for weapons, uniforms, medical supplies, food and other materials, so these needs became an increasing problem. Development of the supply system can be seen through several phases, and these phases share common characteristics, but differ in the ways and sources of supply. With the development of the war and the National Liberation Movement, there was a need for the development of the economy, and background organizations, so that such a mass system could function. The ultimate goal of the partisan economy was to supply the front, but also to address the needs of the population. Although the economy was not as developed as with well-organized armies, it still showed good final results, and laid the foundations for the creation and reconstruction of the Federal People’s Republic of Yugoslavia.