In addition to her gymnastics success, Čáslavská was known for her outspoken support of the Czechoslovak democratization movement and her opposition to the 1968 Soviet-led invasion of Czechoslovakia. At the 1968 Olympics in Mexico City, she took this protest to the world stage by quietly looking down and away while the Soviet national anthem was played during the medal ceremonies for the balance beam and floor exercise event finals. While Čáslavská's actions were applauded by her compatriots, they resulted in her becoming a "persona non grata" in the new regime. She was forced into retirement and for many years was denied the right to travel, work and attend sporting events.