The OSCE had warned ahead of the vote that shortcomings in legislation and the implementation of laws combined with a virtual stranglehold on the media to give incumbent President Imomali Rakhmonov a huge advantage over four little-known rivals.
Rakhmonov won in a landslide, with over 79 percent of the vote, according to official figures.
In a statement issued on November 14 and posted on its website, the EU Presidency acknowledged that the vote showed progress on the 1999 election, when Rakhmonov emerged with 96 percent support.
But the recent vote "lacked meaningful competition," it said.
Three major opposition parties dismissed the election as undemocratic and did not field or back candidates, and discouraged voter participation.
Rakhmonov has been ruling Tajikistan since 1992, and is eligible to run for a fourth seven-year term under the terms of a referendum that Western monitors have rejected as undemocratic.
Monitors from the CIS praised the vote, noting only minor infractions that they claimed did not significantly affect the outcome.
Rakhmonov's inauguration is scheduled to take place on November 18.