Last year, West Midlands Police and Crime Commissioner (PCC) Simon Foster vowed to overhaul stop and search powers as part of his plan to make policing in the region more inclusive.
But a new report shows disproportionality has got worse since he was elected in May 2021.
A report to Mr Foster's strategic crime board shows black people are now 4.4 times more likely to get searched than white people, compared to 3.9 in the year to April 2021.
And the Asian search ratio now stands at 2.7, up from 2.6.
Speaking at a meeting of his strategic board, Mr Foster said: "I am disappointed to see that disproportionality has deteriorated, rather than improved.
"I will be working with West Midlands Police to identify what action needs to be taken to remedy this as a matter of urgency."
The report says the force's lead for stop and search will "continue to track and manage" its use to "further understand the disproportionality".
Chief Constable Sir David Thompson said a "partial explanation" for the disproportionality in stop and search was that crime rates were often higher in areas where ethnic minority communities lived.
Police were usually more active in those areas, he said.
"We either have to be able to explain why we are disproportionate, or we need to do something about it," he added.
The report said the use of stop and search by West Midlands Police officers went up 3.8 per cent in the year to April 2022, with 27,061 searches recorded.
Of those, 548 strip searches were conducted, including 28 on young people.
Labour PCC Mr Foster sparked fury last year after he questioned the effectiveness of stop and search in his police and crime plan.
He suggested many searches conducted by officers may not meet the 'reasonable grounds' threshold. He pledged to increase the rate of "positive outcomes" and to reduce "ethnic disproportionality" in how the powers are used.
The comments drew criticism from Tory MPs, with Nicola Richards, Conservative MP for West Bromwich East, warning that reducing the powers would lead to more weapons on the streets.
The force is in the midst of a review of Section 60 usage, which allows officers to stop and search a suspect without suspicion.
Meanwhile a scheme is under consideration to allow members of the public access video footage of their search.