The deal is said to be for two years though the exact value was unknown.
Fox Sports Florida had reported on Tuesday that Dalembert was about to re-sign with the Sacramento Kings. The Kings issued a press release on Wednesday saying they had withdrawn their offer to Dalembert.
The Rockets thought they had their new man in Pau Gasol, whom they briefly had the rights to via a trade with the Lakers involving Chris Paul and the New Orleans Hornets. When that trade was vetoed by David Stern, the Rockets turned to Plan B and Dalembert.
Houston has a tall task in replacing center Yao Ming, who retired last season.