The main purpose in this study was to examine the correlations between knowledge-sharing motivation, willingness, and behavior of volunteers and paid staff in different types of social welfare nonprofit organizations. Statistical analysis of empirical data from 375 participants' questionnaires revealed the following results. Only one of the hygiene factors, extrinsic motivation, was found to be unrelated to willingness to share knowledge. All other hygiene factors were significantly related to knowledge-sharing willingness behavior, and the intrinsic motivation factor had the strongest influence on knowledge-sharing willingness and behavior.