Objective: While most existing health literacy (HL) measures focus primarily on reading comprehension, the functional, communicative and critical HL scales from Ishikawa et al.  aim to measure a broader HL spectrum. The objective of this study was to evaluate the validity of the Dutch translation of this instrument. Methods: Two survey studies (n = 79 and n = 209) and one cognitive interview study (n = 18) were performed among samples of breast cancer patients and patients with rheumatic diseases. Results: Analyses showed the scales measured three distinct factors and convergent validity was satisfactory for communicative and critical HL. Nevertheless, the comprehension of the items and the suitability of the response options raised some problems. Conclusion: The HL scales seem promising to measure a broad definition of HL. By revising some of the items and response options as proposed in this article, the scale will become more understandable for people with low HL skills, which might increase the content validity and the distributional properties of the scale. Practice implications: The scale should be revised and revalidated. An improved version should be used in practice to gain insight into HL levels of patients. This will help to develop suitable education programs for people with low HL skills.