Radiation protection in paediatric radiology deserves special attention since it is assumed that children are more sensitive to radiation than adults. The aim of this work is to estimate the entrance skin dose (ESD), the body organ dose (BOD) and the effective dose (E) for chest x-ray exposure of paediatric patients in five large units, three in Sudan and two in Brazil, and to compare the results obtained in both countries with each other and with other values obtained by some European countries. Two examination projections have been investigated, namely, postero-anterior (PA) and antero-posterior (AP). The age intervals considered were: 0-1 year, 1-5 years, 5-10 years and 10-15 years. The results have been obtained with the use of a software called DoseCal. Results of mean ESD for the age interval 1-5 years and AP projection are: 66 microGy (Instituto de Pediatria e Puericultura Martagão Gesteira--IPPMG Hospital), 41, 86 and 68 microGy (Instituto Fernandes Figueira--IFF Hospital), 161 microGy (Omdurman Hospital), 395 microGy (Khartoum Hospital) and 23 microGy (Ahmed Gasim Hospital). In the case of the IFF Hospital, the results refer, respectively, to rooms 1, 2 and for the six mobile equipments. The reference dose values given by the European Guidelines were exceeded in the Khartoum Hospital whilst in all the other hospitals results obtained were below CEC reference values and comparable with the results found in Sweden, Germany, Spain and Italy. The mean E for the same age interval was 11 microSv in the IPPMG, 6, 15 and 11 microSv in the IFF, respectively for rooms 1, 2 and the 6 mobiles, 25 microSv in the Omdurman Hospital, 45 microSv in the Khartoum Hospital and 3 microSv in the Ahmed Gasim Hospital. These are some examples of the large discrepancies that have been detected in this survey.