Objective: The overriding objective is a critical examination of Munchausen syndrome by proxy (MSBP) and its closely-related alternative, factitious disorder by proxy (FDBP). Beyond issues of diagnostic validity, assessment methods and potential detection strategies are explored. Methods: A painstaking analysis was conducted of the MSBP and FDBP literature as it relates diagnostic and assessment issues. Given the limitations of this literature, extrapolations were provided from the extensive theory and research on malingering as a related response style. Results: Diagnostic formulations for both MSBP and FDBP de-emphasize the clinical characteristics of the perpetrator. In the case of FDBP, inferential judgments about motivation (e.g., adoption of a sick role) are challenging on conceptual and clinical grounds. When explanatory models from malingering are applied, most research has focused pathogenic models, often allied with psychodynamic thought. Finally, clinical methods for the assessment of MSBP and FDBP are not well developed. Conclusions: Refinements in the conceptualization of MSBP and FDBP can be provided through prototypical analysis. Drawing from malingering research, explanatory models should be expanded to include adaptational and criminological models. Finally, detection strategies for MSBP and FDBP must be formally operationalized and rigorously validated.