There is a need of standardized and quantitative clinical assessments of ALS patients receiving new treatments. Some clinical scales, that are based on patients interviews and/or on physical examination, allow to quantify the patient functional status over time. The ALSFRS has been validated for that purpose and is one the most commonly used scales in clinical trials. Its revised version (the ALSFRS-R) has recently shown excellent metric properties. Functional scales are part of the clinical evaluation of ALS patients, and complete the quantitative assessment of muscle strength, that includes the Manual Muscular Testing (MMT) and the Maximal Voluntary Isometric Contraction (MVIC). Readers will find in this article a (non-exhaustive) listing of functional and motor scales that can be useful both in clinical trials of experimental agents and in daily practice.