SummaryObjective: Analysis of epidemiological data concerning GSD I in Tunisia. Subjects and methods: All the cases diagnosed as GSD I between 1992 and 2005 in a paediatric department recruiting all the metabolic diseases referred from the North of Tunisia were reviewed. Individual data (sex, socioeconomic and educational background, geographic origins, insurance coverage) were collected and pedigrees were reconstituted. Results: Twenty‐two cases (9 boys and 13 girls from 20 homes) were identified. Fourteen belonged to 11 families originating from the North of Tunisia; ten of them are still alive. Both parents in 4 homes (21%) and one parent in 9 homes (47%) were illiterate. Most of the homes (60%) had a low income and 45% comprised at least 3 children. Only 7 homes (35%) had health insurance. Pedigrees indicated 44 infant deaths and at least 10 other cases fulfilling the clinical features of GSD I but not diagnosed. Conclusion: The paediatric prevalence of GSD I in the North of Tunisia can be estimated to 7.93 cases per one million inhabitants and its incidence to 1/100 000 births. However, it is likely to be more frequent because of underreporting or underdiagnosis leading to precocious deaths.