Background: Children adopted from care often exhibit behavioural difficulties. There is however limited cost‐effectiveness evidence regarding different interventions to address this. This paper reports a cost‐effectiveness analysis of parenting programmes for these children. Method: Adoptive parents of children aged between 3 and 8 years participated in home‐based, manualised, parenting programmes delivered by trained family social workers. The adopters were randomly allocated to one of two interventions (n=19) or to a ‘services as usual’ control group (n=18). Baseline, immediate post‐intervention and 6‐month follow‐ups were assessed by questionnaires and adopter interviews. Economic costs were calculated. Results: At 6‐month follow‐up, a significant difference (p<.007) was found for ‘satisfaction with parenting’ in favour of the intervention group. No significant differences were found on child measures between the combined intervention groups and control group, adjusting for baseline scores. The mean costs for the combined intervention group were £1528 higher than for the control group at the post‐intervention point, which was statistically significant (95% CI, £67 to £2782). However, over the entire follow‐up period the difference (£1652) was not statistically significant (−£1709 to £4268). The cost‐effectiveness analysis showed that costs of £731 would be incurred to achieve a point improvement in satisfaction with parenting compared to routine care by the end of treatment, whilst the figure was £337 for a point improvement by the 6‐month follow‐up. Conclusions: Findings suggest that a home‐based parenting programme for adopters caring for difficult children in the first 18 months of placement may be cost‐effective in enhancing satisfaction with parenting, but not in reducing child behavioural problems, compared with ‘services‐as‐usual’.