Introduction Congenital heart disease is the commonest type of birth defect of which the estimated prevalence is around 8–12/1,000 worldwide. Caregivers of children with congenital heart diseases are easy victims of high economic burdens and economic instability. Objective The aim was to describe the household economic cost for a clinic visit, of primary caregivers having children with CHDs who are awaiting cardiac surgery attending a cardiology clinic at a major pediatric hospital in Sri Lanka. Methodology A descriptive cross-sectional study was conducted over three months among 427 samples of caregivers of children with congenital heart diseases at Cardiology clinic, Lady-Ridgeway Hospital Sri Lanka. A consecutive convenient sampling method was used to recruit the participant and economic cost was developed based on previous studies, surveys and opinions of an expert in economics. Results Out of caregivers, 75% were unemployed, and the median income was ₹30,000. The median direct cost per clinic visit was ₹1,800. A large proportion of direct cost was showed in traveling expenses. The median indirect cost was ₹1,000. Of the caregivers, 28.7% were falling into catastrophic expenditure during that particular month of the clinic visit. The mean waiting time per clinic visit was 53 minutes. Statistically significant association found distance with transport cost (Chi-square value = 25.14, df = 1, p & .001, OR = 3.4 (CI: 2.1–5.5). There was no statistically significant association between the income of the caregiver and expenditure (Chi-square value = 0, df = 1, p = .998, OR = 1 (CI: 0.678–1.473). Conclusions Assessment of economic burden and its associated factors is vital to recognize high-risk caregivers early, and improvement of monetary support methods.