This study compares the results of a full mouth examination with the results of examining only the CPITN selection of 10 index teeth 17/16, 11, 26/27, 47/46, 31 and 36/37 for estimates of prevalence and severity of the conditions assessed with the CPITN, i.e. gingival bleeding, dental calculus, pockets 4-5 mm deep and pockets 6+ mm deep. The mean number of sextants recorded with bleeding or with calculus was generally overestimated when examinations were based on the CPITN selection of index teeth, whereas the mean number of sextants with pockets, whether moderate or deep, were generally underestimated. Similarly, the prevalence of pockets, whether moderate or deep, was underestimated in virtually all age groups while the prevalence of calculus was overestimated in all age groups and the prevalence of bleeding was overestimated among persons below 30 yr of age. We conclude that the partial recording approach of the CPITN methodology is reasonably well suited for identifying persons who are relatively healthy according to the hierarchy of the CPITN parameters. There is, however, a considerable risk that persons presenting with the more severe conditions, i.e. pockets, will be overlooked if only partial recordings are performed.