Mixed accommodation is having a disproportionate affect on older and vulnerable members of society.
This is the view of Caroline Bernard, deputy chief executive at Counsel and Care.
Her opinion follows news from the government that NHS hospitals are still placing "tens of thousands" of people in mixed sex-accommodation every year without clinical justification.
Ms Bernard said: "It is clearly important that, to preserve dignity, men and women should be cared for on separate wards as far as possible, unless they have specific needs such as intensive care."
Commenting on promises from the coalition government to change the situation, she said: "Past governments have made these pledges, and in far better financial circumstances than we are in today."
The health professional noted that the vulnerable and older members of society are the biggest users of inpatient services and that the Counsel and Care is looking forward "to a time when mixed accommodation is eliminated once and for all" for this section of society.