"Let's Do It!" organizers say Saturday's annual event turned out 1,522 initiatives and 36,270 volunteers in Estonia.
Volunteers across the country cleaned up villages, nature reserves, cultural landmarks, hiking paths and sports facilities.
Tallinn had the most participants - 10,582 according to a statement from the organizers. But less populated areas also saw high participation levels, with 3,160 on Saaremaa and 2,849 in Pärnu.
Meanwhile on Saturday, President Toomas Hendrik Ilves visited Canada's Estonian community, which was also taking part in the initiative.
"Let's Do It!" began as a grassroots cleanup initiative in Estonia in 2008 and later went on to become a successful global project attracting millions of participants from 96 countries in 2012.