Gabriela Isler was crowned Saturday night in the pageant at a sprawling exhibition hall on Moscow's outskirts.
In the excitement just after the announcement, the tiara fell off Isler's head as she was being crowned by Miss Universe 2012, Olivia Culpo of the United States. Isler caught the crown laughing.
Patricia Rodrigues of Spain was the runner-up.
The panel of judges was led by Steven Tyler.
Venezuelan President Nicolas Maduro congratulated Isler on Twitter, calling her title a "triumph" for Venezuela, a country that has now won three of the last six Miss Universe pageants.
In fact, Venezuela has won more major international beauty competitions than any other nation, and beauty pageants rank alongside baseball as the country's most-followed diversion, one that transcends social class and normally insurmountable political divisions.
A whole industry of grooming schools, plastic surgeons and beauty salons has emerged to prepare young women for the thousands of pageants that take place each year around the country in schools, army barracks and even prisons.