The report by the Vienna-based organization says such activists are subjected to intimidation, surveillance, defamation campaigns, torture, ill treatment, and imprisonment.
It says their relatives are also persecuted by Uzbek authorities.
The report calls on the EU to make any weakening of sanctions imposed on Uzbekistan in late 2005 conditional on concrete steps by Tashkent toward ending such persecution.
The organization says its report is primarily based on first-hand information obtained during a recent fact-finding mission to Uzbekistan.
It is to be presented at a meeting of the Subcommittee on Human Rights of the European Parliament in Brussels on February 28.