Objective To identify the risk factors of cognitive frailty in community-dwelling elderly people with chronic diseases, and to provide reference for targeted interventions. Methods Totally, 674 community-dwelling older people with chronic diseases were investigated by using a self-designed sociodemographic data questionnaire, Fried′s Frailty Phenotype, the Montreal Cognitive Assessment, Clinical Dementia Rating scale, Short-form Mini-Nutritional Assessment and Geriatric Depression Scale-Short Form. Risk factors of cognitive frailty were identified through Chi-square test and multivariate logistic regression, then a nomogram based on the risk factors was constructed and validated with bootstrap resampling. Results The prevalence of cognitive frailty in community-dwelling elderly with chronic diseases was 33.5%. Age, living alone, malnutrition, depression and physical exercise were the main predictors (P<0.05 for all). The calibration curves for the probability of cognitive frailty showed optimal agreement between the probability as predicted by the nomogram and the actual probability.The nomogram showed a robust discrimination, with an area under the receiver operating characteristic curve of 0.970. Conclusion The prevalence of cognitive frailty was relatively high in community-dwelling elderly with chronic diseases. Advanced age, living alone, malnutrition and depression were risk factors, whereas physical exercise was protective factor. Validation by the use of bootstrap resampling revealed optimal discrimination and calibration, indicating that the nomogram can be used as a screening tool.