The aim of this study was to investigate the effects of a counselling-based dietary intervention on nutritional status in partially dentate patients receiving removable partial dentures (RPDs). Thirty-eight patients [mean age (standard deviation): 73.2 (7.7) years] who were scheduled to receive RPDs at a dental hospital and were currently eating <350 g of vegetables per day were included in the study. A dentist provided basic dietary counselling aimed at increasing dietary fruit and vegetable intake and improving dietary habits. Patients received dietary counselling directly after treatment with new RPDs and at 1 week after a 1-month follow-up evaluation (T1). Food intake was assessed via a validated brief-type self-administered diet history questionnaire, and carotenoids and vitamin C in 6-hour fasting blood samples were measured before RPD administration, and at 1 (T1) and 3 months (T3) thereafter. Vegetable but not the fruit intake increased significantly at T1 and T3 compared to before treatment. Alpha carotene significantly increased at T3 while β significantly increased both at T1 and T3 compared to before treatment (P < .05). The number of occlusal units on natural teeth was significantly positively associated with increased vegetable and β-carotene intake (P < .05). Serum carotenoids and vitamin C levels measured with 6-hour fasting blood samples remained constant. These results suggest that basic dietary counselling may improve vegetable intake in partially dentate patients receiving RPD treatment, but did not lead to haematological changes. The presence of occlusion of remaining posterior teeth may be critical for improving vegetable intake.