summary  The aims of the study were to assess oral health‐related quality of life (ohqol) impact among patients with severe hypodontia and to determine the association between ohqol and the number of missing teeth. Twenty‐five patients with severe hypodontia (four or more missing permanent teeth) self‐completed the child perception questionnaire (CPQ) to assess oral symptoms (OS), functional limitation (FL), emotional well‐being (EWB) and social well‐being (SWB). Correlation between CPQ scores (overall and at domain level) and the number of missing teeth was assessed. All participants reported ohqol impact, 100% reported experiencing OS, 88% FL, 55% EWB and 100% SWB impacts. The correlation between the number of missing permanent teeth and the CPQ scores was moderate: overall CPQ score (r = 0·54), OS (r = 0·41), FL (0·52), EWB (0·52), SWB (0·49), P < 0·05. Having accounted for retained primary teeth (where a retained primary tooth was considered to have compensated for a missing permanent tooth), the correlation between the number of missing teeth and CPQ scores was strong: overall CPQ score (r = 0·94), OS (r = 0·78), FL (0·88), EWB (0·92), SWB (0·70), P < 0·001. Subjects with severe hypodontia report considerable ohqol impact. The number of missing permanent teeth was moderately correlated with ohqol. However, when retained primary teeth were taken into account, the number of missing teeth was highly correlated with ohqol. This study has implications in understanding the impact of hypodontia on quality of life and highlights the importance of retaining primary teeth in children and adolescents with severe hypodontia.