Goal Attainment Scaling (GAS) is a person-centered and collaborative approach, allowing to assess the effectiveness of an intervention on personally relevant goals. However, GAS is not a "scale" but a heterogeneous group of methodologies, including many variations and lack of consensus on high quality GAS. The aim of this communication is to: 1. provide updated didactical information on GAS use in PRM practice and research; 2. increase awareness of GAS methodological challenges; 3. guide use of GAS as an integrated process of rehabilitation after goal setting and; 4. provide updated resources for self-directed learning and extensive supplemental material to increase knowledge and practical skills in GAS use. Educational literature review about current GAS applications relevant to PRM fields. Practical advice is provided regarding clinical challenges in GAS: definition of 0 level, time-frame and means employed to attain the goal, dealing with unforeseen pattern of improvement, synthesizing the numerous significations of "SMART" goal acronym to guide best use of GAS, and thinking flexibility on the type of relevant goals that can be set. Challenges with GAS in rehabilitation research are presented in order to promote researcher's and reviewer's awareness on reliable use of GAS and encouraging best-use of GAS.