It is one of 30 mental health trusts nationally to rated excellent
A mental health trust in East Yorkshire has been judged as one of the highest performing in the country in the annual review of NHS services across England.
It is the second year running that Humber Mental Health Teaching NHS Trust has been rated as "excellent" for its quality of services.
Chief executive David Snowdon said he was delighted with the result.
Hull and East Yorkshire Hospitals NHS Trust has dropped from "good" to "fair" for quality of services.
Meanwhile Scarborough and North East Yorkshire Healthcare NHS Trust, which covers Bridlington, has improved from "weak" to "fair".
Humber Mental Health trust provides care for people with mental health, learning disability and addictions in Hull and East Yorkshire.
It is one of 30 mental health trusts nationally to achieve a rating of excellent.
The trust maintained its previous mark of "good" for its financial management.
Mr Snowdon said: "These results are entirely down to the outstanding efforts our staff make on a daily basis."
It is the fourth year the CQC has carried out its annual assessment of the NHS.
It is based on the trusts' performance between 1 April 2008 and 31 March 2009 and rates each organisation as excellent, good, fair or weak on both its quality of services and financial management.