We sought to better define the demographics and characteristics of post-transplant lymphoproliferative disorders (PTLD) in a cohort of paediatric OHT patients from a developing country. Data were collected from the Heart Institute, Sao Paulo, for all paediatric OHT recipients from October 1992 to October 2018. Group differences between the PTLD and non-PTLD cohorts were assessed by Fisher exact and Mann–Whitney U tests. Kaplan–Meier curves analysed the survival in each group. Data were reviewed for 202 paediatric OHT recipients. Overall 1-, 5- and 10-year survival for the entire cohort was 76.5%, 68.3% and 62.9%; 24 patients (11.9%) developed PTLD at a median 3.1 years (IQR 0.8–9.0) after OHT. Cases were evenly spread over the follow-up period, with PTLD diagnosed in 9.8% (n = 137) of patients who were alive at 3 years, 15.3% (n = 78) of patients who were alive at 5 years and 29.3% (n = 41) of patients who were alive at 10 years. The commonest form of PTLD was diffuse large B cell lymphoma (n = 9), and most patients received rituximab with immunosuppression and chemotherapy as treatment (n = 15). We identified no increased risk in mortality amongst the PTLD vs. non-PTLD cohorts in multivariate analysis (P = 0.365). PTLD after paediatric OHT had acceptable outcomes. However, risk factors for PTLD were not identified and warrant further investigation.