An officer of the Polish Army, he was trained at the Polish Higher Infantry School and the General Staff Academy, and joined the Polish United Workers' Party (the former Polish Communist Party), of which Central Committee he became a member in 1964. Soon he was also named the minister of defense.
In 1968 he led invasion on Czechoslovakia. In 1970 was involved in the plot against Wladyslaw Gomulka, probably took part in organisation of the massacre in the coastal cities of Gdansk, Gdynia, Elblag and Szczecin.
Jaruzelski became the party's national secretary in 1981, when Lech Walesa's movement (Solidarity) was starting to earn national and external popularity. Under Jaruzelski's inspiration and pression, a martial law was issued to contrast the increasing political relevance of Solidarity, but finally after a few years, at the beginning of the 1990s, the movement was legally recognized.