The COVID-19 pandemic has led to unprecedented economic and health vulnerability and inequities globally. This study aims to determine the out-of-pocket (OOP) expenditure of families of children with cancer in Peru before and during the COVID-19 pandemic. We conducted a cross-sectional survey of 235 parents and caregivers of children diagnosed with cancer in Peru. Our study suggests that OOP expenses in these families constitute a catastrophic expense for health. This situation was aggravated due to a decrease in the economic income for most families due to the disruption in formal and informal employment.