Accidents occur in laboratories due to a lack of proper knowledge regarding laboratory safety measures, perilous attitudes, and unacceptable laboratory practices. This study assessed the chemistry laboratory safety knowledge, attitude, and practice (KAP) of teachers and laboratory technicians in secondary schools of South Wollo, Ethiopia. The sample included 300 chemistry teachers and 76 laboratory technicians selected using stratified random sampling technique. Data were collected using academic achievement test, questionnaires, observational checklists, and document analysis. The findings revealed that knowledge of teachers and laboratory technicians was scored as moderate (57.08%) and good(60.28%), respectively. The attitude of teachers was good (62.59%) and that laboratory technicians was excellent (71.55%). However, the practices of laboratory safety among teachers and laboratory technicians were inadequate. The cumulative percentage of teachers (45.37%) and laboratory technicians (48.59%) indicated that the practice of chemistry laboratory safety in respective schools was very poor and below the standard level. The practice of personal protective equipment and waste management was not properly implemented in the schools, and no adequate individual safety training was arranged for teachers and laboratory technicians. Safety equipment was not sufficiently available, and emergency exits were not clearly marked. The statistical t test indicated that teachers' KAP was not significantly different from laboratory technicians. Finally, the study recommended possible remediating strategies such as cooperative lab work, audio-visual based interventions, prepare standardized laboratory manual, formulating chemical inventory and inspection groups, updated chemical safety education and training, and fulfillment of safety equipment to promoting a stronger laboratory safety culture in secondary schools.