This study investigated the effects of school-level and individual-level factors influencing the participation and nonparticipation of secondary school teachers in continuing professional education (CPE). Researchers randomly selected 25 out of Hong Kong's 442 secondary schools to participate. All teachers in the schools were invited to complete a questionnaire, and 839 out of 1,364 teachers responded with usable questionnaires (373 participants, 427 nonparticipants, and 44 intended participants). The questionnaire examined: (1) school level-factors (school culture regarding CPE, school size, school socioeconomic status, client power, and job environment); (2) personal-level factors (attitude toward CPE, motivations, and personal demographics); and (3) teacher-school fit factors (job performance, job satisfaction, and school commitment). Data analysis indicated that all of the school-level factors except one were insignificant in influencing teachers' participation or nonparticipation in CPE. Although principals' influence was significant, the effect was negative. Most of the impact on CPE participation was found at the individual-level. Income exerted an outstanding negative impact. The motivation for promotion exerted a strong impact. Motivation for new and interesting things in life and at work and better job fulfillment had a negative impact on CPE participation. The teacher-school fit factors were totally insignificant in affecting CPE participation. (Contains 50 references.) (SM)