Introduction This paper describes the usability of mobile shower commodes for adults with spinal cord injury, as measured by the new electronic Mobile Shower Commode Assessment Tool Version 1.0 (eMAST 1.0). Method A retrospective analysis of data collected for a cross-sectional validation study with adults aged 18 years or older, living with spinal cord injury, who use mobile shower commodes for toileting and/or showering ( n = 32), was conducted. Usability was measured using the eMAST 1.0. Quantitative data were analysed using descriptive statistics. Qualitative data were analysed using directed content analysis. Results Overall usability on both the features and performance subscales was rated as high to very high. Ratings of very low to low usability were reported for portability/foldability/packability (41%, n = 13), mobile shower commode stability (25%, n = 8), positioning and repositioning (25%, n = 8), seat cushioning (25%, n = 8), and lower leg supports (22%, n = 7). Items receiving the highest number of qualitative comments included lower leg supports, seating, propelling and manoeuvring, cleaning and maintenance, and stability. Conclusion Results across the eMAST 1.0’s subscales showed high to very high usability. However, analysis of individual items and qualitative comments showed specific areas of reduced usability for individual users. Item-level responses and qualitative comments suggest research is urgently needed in the areas of stability, portability, durability, and seating. Studies exploring use of the eMAST 1.0 during initial provision, and after short- and long-term mobile shower commode use, are also needed.