The purpose of this study was to develop a workwear design that takes into account the characteristics of people with severe developmental disabilities who can engage in vocational activities. The aim was to identify needs according to the specific characteristics of people with severe disabilities to design work clothes and develop products according to universal design guidelines. This research method was conducted through representative interviews from a company employing people with severe disabilities in Daegu to determine the requirements for workers-related work clothes, and then applied universal design guidelines to perform appropriate design. The results of the study show that the hygiene and warmth of clothing are important for people with developmental disabilities. Therefore, the use of bright materials is required. Second, people with brain lesions often have low body temperature due to difficulties with blood circulation, for which warmth is a required factor. Third, people with severe developmental disabilities should not be differentiated in comparison to people without disabilities, therefore, it was important to use nondiscriminatory designs. Accordingly, it was more efficient to modify and supplement clothing designed for non-disabled people with hidden functions to suit specific characteristics, rather than to develop specialized clothing. These demands were found to conform to what is referred to as a universal design concept, through which three nondiscriminatory shirt designs and two easy-to-use pants were designed.