Mr Straw said he was 'aware' the judiciary was dominated by white men
Too few women and people from black and Asian backgrounds are appointed judges, Jack Straw has told MPs.
The justice secretary said the Judicial Appointments Commission (JAC), formed two years ago, had so far failed to create a "more diverse judiciary".
Concerns about white, middle class men dominating the bench were justified, he told the Justice Select Committee.
Mr Straw said he was determined to ensure that the judiciary represented wider society better.
"The expectation that a new system would lead to a more diverse judiciary has so far not been fulfilled," he said in evidence to the committee.
"The chairman of the JAC and I are very well aware of that.
"We are determined to do everything that we can to ensure that amongst the wider benefits of the new judicial appointments system there is a much more diverse judiciary."
Figures released last month showed the numbers of women and people from ethnic minorities being made judges under the new appointments system were lower than previous levels.
Jack Straw addresses the Justice Committee
The JAC said 8% of the people it recommended for judicial jobs last year were black or Asian.
In contrast, between 14% and 15% of lawyers appointed annually in the two years before the JAC was established were from these ethnic groups.
In addition, 156 women were chosen for appointment under the new system, making up 34% of the total. This compares with 41% in 2005/06.
The JAC, which appoints judges in England and Wales, was established as part of reforms to make judicial appointments more "transparent and robust".
At the committee hearing, Mr Straw also revealed a consultation paper on controversial plans for three huge so-called "Titan" prisons is due to be published next month.
The government wants to build the jails in south-east England, the North West and West Midlands - each housing about 2,500 inmates.
Chief Inspector of Prisons, Anne Owers, has criticised the plans saying she did not think "prison building should be driving our prison policy".
Mr Straw pledged to listen to all views expressed in the consultation.