The sisters lost 2-6 6-1 (10-8) on Monday to Ukraine's Marta Kostyuk and American Peyton Stearns, coming back from 6-0 down in the tiebreaker before a double-fault by Venus sealed their fate.
"I thought it was fun, I thought it was special, I thought it was good," Serena, 44, told reporters.
"We kicked off a little rust in the middle of the match. We were starting to feel it, and it was really fun. It was really cool to be able to do this again."
The Williams sisters have won 14 major doubles titles, including six at Wimbledon and three Olympic gold medals.
They last played doubles together at the 2022 US Open, where they lost to Czechs Lucie Hradecka and Linda Noskova.
The Americans were due to compete in the doubles draw at Wimbledon, but were forced to pull out after Serena sustained a knee injury during her opening-round singles defeat.
They were awarded a wild card for Cincinnati earlier this month.
"I think we've waited a long time to get back on the doubles court, even this year. Eventually, we find our way to each other," Venus, 46, added.
Venus also competed in the singles draw in Cincinnati, where she was beaten 6-2 6-2 by Colombian Emiliana Arango.
