Purpose: This study compared the chewing difficulty of foods in diets of denture wearers with mandibular conventional and implant-supported overdentures. Materials and Methods: One-week dietary logs were evaluated for 58 subjects with controlled diabetes at baseline with their original dentures and with new dentures 6 months after treatment completion. Subjects received new maxillary and mandibular complete dentures, 21 with mandibular conventional dentures and 37 with implant-supported overdentures. A 10-point chewing difficulty rating scale (10 for most difficult-to-chew foods) was used to rate food items in the dietary logs. Results: ANOVA showed no differences between the chewing difficulty mean scores for all foods consumed either at baseline or posttreatment for the two groups. However, the mean scores for the combined consumption frequency of difficult-tochew foods (6 to 10) showed a significant decrease following treatment with both types of dentures. This decline did not differ significantly between the denture types. With original dentures, more than 91% of subjects consumed foods with chewing difficulty scores of 6 to 10 at least seven times per week. With study dentures, only 21% maintained this level of consumption, with the frequency decreasing to four to six times per week in 24% and one to three times per week in 43% of subjects. The declines in consumption frequency of more difficult to chew foods with study dentures were in a higher percentage of subjects in the implant than in the conventional group. Conclusion: After 7 months of adaptation to new dentures, patients consumed fewer difficult-to-chew foods than with their original dentures. This decline was more frequent with mandibular implant-supported overdentures than with conventional dentures. Dietary counseling should be considered as part of implant and complete denture therapy. Int J Prosthodont 2003;16:609–615.