The relationship between oral hygiene, dental caries experience, periodontal condition and socio-economic status was assessed in 1375 13-14-year-old school children in Irbid Governate, north Jordan. They were divided into four groups according to their family income: 'very poor', 'poor', 'moderate' and 'rich'. Their oral hygiene, dental caries experience and peridontal status were assessed using the Silness and Loe plaque index (PI), the decayed, missing and filled teeth or surfaces (DMFT/S) system and the Community Periodontal Index of Treatment Needs (CPITN), respectively. The mean PI was 1.82 but there was a trend to decrease gradually from the 'very poor' to the 'rich' group There were no significant differences in caries experience between the four groups. The CPITN showed that the 'very poor' group had a slightly lower mean number of healthy mouth sextants than the other groups, but slightly higher scores for bleeding, calculus and pocketing. The results reveal that socioeconomic status, as assessed by family income, seems to have little relationship to dental caries experience or periodontal disease in 13-14-year-old school children, in north Jordan.