Inflammation in patients defined as frail by Fried’s phenotypic definition may be related to sarcopenia. This study aimed to investigate inflammation in older patients across different frailty criteria. Frailty status was determined in 110 patients aged over 75 years (mean 83.9 years) according to function (dependent, intermediate, independent); Fried (three or more items of exhaustion, weight loss, slow walking speed, low handgrip strength, low physical activity) and Frailty Index (a measure of accumulated deficits). With increasing patient frailty as defined by function and by Fried phenotype, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and C‐reactive protein (CRP) increased significantly. Albumin was lowest in the frailest subjects by each definition. The greatest differences were seen between intermediate and dependent groups and between the pre‐frail and frail. Adjustment for multiple covariates (age, sex, BMI category, smoking status, number of co‐morbidities and number of prescribed medications) did not account for any of the observed differences in levels of inflammatory markers. The Frailty Index correlated significantly with log‐transformed CRP (r= 0.221, P < 0.05), log‐transformed IL‐6 (r= 0.369, P < 0.01), TNF‐α (r= 0.379, P < 0.01) and inversely with albumin (r=– 0.545, P < 0.01). This study provides further evidence linking inflammation and frailty in older people, an association that seems consistent across different frailty measures.