Peter Clarke, who is halfway through his seven-year term as the UK's first commissioner, also announced plans to carry out a comprehensive study of bullying.
And he fired some shots across the border at the Westminster government, which he has criticised previously for giving its proposed children's commissioner for England fewer powers than he has (TES Cymru, November 12).
Staff shortages in social services mean that, in some areas of Wales, children at risk of abuse have not been allocated a social worker. Mr Clarke believes red tape, media portrayals of social workers and poor pay all contribute to recruitment difficulties.
"This constitutes a real danger for these children, and this situation now constitutes an emergency," he says in the report.
He also notes that only 10 councils have so far created a children's complaints officer. This was a key recommendation of Lost in Care, the report on child abuse cases in North Wales children's homes, and also of a more recent report, Telling Concerns, from the commissioner's own office.
And he is highly critical of mental health services for children and adolescents, saying an extra pound;700,000, announced by health minister Jane Hutt, is "totally inadequate".
The commissioner's plans for a study of bullying follow the death of Laura Rhodes, the Neath teenager who died in a suicide pact with a friend, who survived. Laura's parents say a contributory factor was the bullying she suffered while a pupil at Cefn Saeson secondary, in Neath.
Head Alun Griffiths has said the school was not to blame for her death, and that it did everything it could for Laura and her family.
Mr Clarke writes: "For some, bullying makes their lives a misery to the point of contemplating suicide. For others, it becomes a daily round of bitter endurance, the effects of which will stay with them for the rest of their lives."
His proposed study will focus particularly on schools and pupils' journeys to and from school. Mr Clarke wants reports of bullying from parents and children to be treated as formal complaints, and for children to have a legal right to an independent advocate while their concerns are being investigated.
He criticises the Welsh Assembly for failing to involve young people in consultations on a key strategy on sustainable development, announced this week.