Aim: To study the association between Insulin Resistance (IR) and Glycosylated hemoglobin (HbA1c) and cognition in frail, pre-frail and non-frail elderly. Method: A case control study was conducted on 85 subjects: 60 cases (37 frail and 23 pre-frail subjects) and 25 controls. All subjects underwent comprehensive geriatric assessment including a battery of cognitive tests. Laboratory data included Serum insulin levels, Fasting Blood Sugar, Insulin like Growth Factor-1, C-Reactive Protein (CRP) and HbA1c. Results: Among the pre-frail subjects, Homeostasis Model of Assessment-Insulin resistance (HOMA-IR) and insulin level were positively correlated with Digit Span Backward (DSB) (p = 0.012 and 0.045 respectively). HbA1c was positively correlated with Contrast Programming (CP) (p = 0.01). Controls showed a positive correlation between HOMA-IR and CP, DSB and Mini-Mental Status Examination (P = 0.009, 0.03 and 0.002 respectively). There was no significant correlation in the frail group. Conclusion: In the studied sample, higher insulin, HbA1c, and IR were associated with better cognitive functions in prefrail elderly, and were not associated with worse cognition in frail elderly.