Dental treatment in children too young or too apprehensive to co-operate is often performed under sedation. The aim of this study was to survey the use of rectal and oral liquid and tablet benzodiazepine sedation in Swedish child dentistry, and estimation of treatment success. A questionnaire was sent to 500 randomly selected dentists (GPs) working in the Public Dental Health Service and all (77) specialists (PDs) working at paediatric dentistry clinics. Benzodiazepine sedation was used by 73% of the GPs and 97% of the PDs. Seven per cent of the GPs and 87% of the PDs had sedation sessions at least once a month. Of the GPs, 60% administered the sedation rectally, 7% orally in liquid form, and 39% orally in tablet form. For PDs, the corresponding figures were 97%, 78%, and 68%. Sixteen per cent of the GPs and 84% of the PDs used midazolam for rectal sedation. PDs rated rectal sedation better than the GPs (p < 0.001). GPs rated their experiences of rectal sedation as better the more frequent the use (p = 0.03), as did PDs concerning oral liquid sedation (p = 0.03). Thus, it seems that a more regular use of sedation is advantageous in achieving better treatment outcome.