The three – Ramathan Govule, Brian Kikaawa and Fred Odur – were not found at the team’s hotel on Monday when they were preparing to leave the country, local media report.
The national rugby team has faced a similar incident after the 2014 Commonwealth Games when two players went missing after the event hosted in Glasgow, Scotland.
Uganda’s Rugby Cranes honoured the invitation of Germany to partake in the Oktoberfest Sevens which kicked off last week Saturday.
They used the opportunity to train for this weekend’s Africa Cup Sevens – the African national rugby tournament – which they won last year.
The disappearance of the three players means the coach needs to find their replacement to get the full 12-man side who will play against Namibia, Botswana, Zimbabwe, Madagascar, Tunisia, Zambia, Ghana, Morocco and Senegal in the Ugandan capital, Kampala.
They could miss out on the Africa Cup Sevens title which offers automatic qualification to the Rugby World Cup.
African teams have a repetitive history of going missing after competitions in Europe and America.
The most recent incident was in July this year when six teenagers from Burundi bolted after participating in an international robotics competition in the United States.
The two females and four males between the ages of 16 and 18 were considered safe after two were found crossing into Canada.
Earlier in April, 15 Cameroonian footballers were detained, fined and ordered to immediately leave Russian territory after attempting to stay in Crimea after a tournament.
In 2016, two members of Guinea’s Olympic team disappeared from the Rio 2016 Athletes’ Village after the competition.
In 2014, four members of an Ethiopian track team competing at an international event in Oregon in the United States went missing in what officials believed was an attempt to seek asylum and stay in the United States.
In 2012, seven Olympic athletes from Cameroon, including 5 boxers, a swimmer and a reserve women’s goalkeeper, were also missing during the London 2012 Olympics. They were followed by three Guineans and three Ivorians, while two members of the Sudanese team and one Ethiopian sought asylum in the UK.