Aim. This paper is a report of a study evaluating the long-term effects on the oral hygiene status of older nursing home residents one and a half years after dental hygiene education was given to the staff. Background. A strong relationship exists between oral infections and general health complications (especially aspiration pneumonia) among nursing home residents and hospitalized older people. It is therefore important to educate nursing home staff in oral hygiene measures and to follow up the effects of the education over time. Methods. Dental plaque measurements were conducted at a Swedish nursing home in 2006-2008. Forty-one residents (12 men, 31 women, aged 69-99 years) fulfilled the inclusion criteria and participated in a dental hygiene evaluation 1·5 years after dental hygiene education was given to the staff at the nursing home. Plaque index scores (year 2008) were compared to those soon after the education (year 2006). Findings. After the dental hygiene education in 2006, 60 nursing home residents (14 men, 46 women) were available for plaque index measurements, whereas 41 residents (12 men, 29 women) were available 1·5 years later. The median plaque index scores were 17·0 ( n = 60) in 2006, and 18·0 ( n = 41) in 2008 (Mann-Whitney U-test, P > 0·05). Conclusion. Dental hygiene education for nursing home staff is important to maintain an adequate level of oral hygiene among older nursing home residents over time. Follow-up of dental hygiene education for nursing home staff is recommended to maintain a sufficient level of oral hygiene among the residents.