Staff at some were negligent and uncaring, ignoring very young children or handling them carelessly, the survey, carried out for BBC1's Panorama, found.
A quarter of staff in the nurseries studied were untrained.
The most profitable nurseries generally provided lower standards of care, according to the programme, to be broadcast tonight.
The survey studied 10 nurseries, drawn from a larger study in 1990. Four were assessed as providing poor care, one was mediocre and five were judged to be of good quality.
Sandra Keevil, of the Under-eights Advisers Association, told the programme: 'There are day-care facilities where children shouldn't be. There are childminders whose standards are very poor indeed, and children should not be placed with them. Potentially, there are thousands of children who are not receiving the kind of quality day care that they should be.'