CONTEXT: Spasticity is an increase in resistance to the passive movement of a joint due to an abnormal increase in muscle tone. Considering the difficulty in assessing spasticity accurately, the isokinetic dynamometer is considered a valid measure for assessment of spasticity in multiple joints. OBJECTIVE: Review of assessment protocols of knee muscles spasticity using the isokinetic dynamometer. DATA SOURCES: Research was performed in the PubMed, SciELO, Academic Search Complete and Scopus databases, in English, French and Portuguese language. Studies were included when spasticity assessment protocols with isokinetic dynamometer for knee muscles were applied. STUDY SELECTION: Eligible studies were the ones assessing spasticity with an isokinetic dynamometer protocol in knee muscle groups and excluded those who failed to meet eligibility criteria. DATA EXTRACTION: Two independent reviewers applied the selection criteria to the retrieved studies to limit the number to the final list. DATA SYNTHESIS: A total of 151 studies were retrieved from the literature search and 8 articles met the inclusion criteria. Included studies assessed spasticity with the resource to the isokinetic dynamometer. All studies applied an assessment protocol using isokinetic dynamometer on knee muscle groups. CONCLUSIONS: The isokinetic dynamometer is a valuable tool in the assessment of spasticity and other conditions of tone change, offering more accurate, reliable data, easily to reproduce and to interpret. The resistance torque values have a high correlation with the Ashworth scale reflecting the clinical condition of the muscular tone.