Background: Current therapies for childhood cancer have resulted in improved survival rates. However, this has been achieved at considerable price to families, with financial costs including additional expenditure and loss of earnings having been described. The impact of these extra costs for UK families and the extent to which help from charities and government benefits is able to alleviate this is unknown. Methods: Questionnaires concerning income, expenditure, employment and financial support were completed by 145 parents, recruited from three United Kingdom Children's Cancer Study Group treatment centres. Results: Parents' responses highlighted increased expenditure related mainly to travel to treatment centres. The majority of families (55%) had spent between £50-100 in the past week over and above pre-illness expenditure, with a further 18% spending more than £100. Many parents (mainly mothers) had either given up or reduced outside employment in order to care for their child and this was associated with further financial problems for 42.7% of families. Despite help from charities and government benefits for the majority of families, extra costs were associated with money worries for 68.3% of families. Conclusions: Although families are offered timely information about their entitlement to benefits, financial problems are incurred by families of a child with cancer partly because legislation prevents benefits being claimed for the first 3 months of a child's illness -the time when expenses are still at their highest. Furthermore, because benefits are backdated only to the point at which the claim was made, families do not recoup all their costs. Waiving of the 84-day wait period for children undergoing chemotherapy and radiotherapy, and the introduction of weekly bridging payments while a Disability Living Allowance claim is being assessed, would ameliorate this problem and so improve the treatment experience for families.