Considering sociopolitical trends in which Croatia was as a part of Yugoslavia, primary education in Croatia from 1945 to 1990 was experiencing many changes. As the awareness about the importance of education was rising throughout the years, the laws upon which today’s school system is based on were also progressing. After the end of World War II, Croatia became one of the federal states in the former FPRY (later SFRY), whose regime consisted of one party and one ideology. In 45 years, Croatian primary education was experiencing changes in the length of compulsory elementary education, from four-year, seven-year, to final eight-year education. These variations affected the changes in the education laws, while the changes in curricula were even more frequent. This paper also describes the influence of political ideology towards children in primary schools. The elements of political ideology were mostly expressed through the Union of Pioneers of Yugoslavia; even in the schools itself, where the most influential tools of transmitting Yugoslavian ideology were textbooks.