This research and development project aimed to develop a guideline for implementation in the prevention of loss to follow up among newly diagnosed pulmonary tuberculosis patients which are appropriate for each TB patient target group characteristic and practices of hospital personnel and hospital context. The project methodology applied collaborative quality improvement concepts of The Institute for Healthcare Improvement (IHI), the USA which consisted of 8 steps including 1) selecting the topic to be improved 2) inviting the experts to participate 3) inviting organizations to participate and establish a team 4) knowledge sharing 5) implement improvement 6) evaluate changes 7) assess and evaluate and 8) conclude outcome and distribution. The duration of the project was one year. Participating hospitals consisted of 17 Regional and General hospitals under the Ministry of Public Health. Hospital personnel who participated in the project consisted of 83 personnel including 10 physicians, 29 registered nurses from TB clinic, 16 pharmacists, 12 social workers, 9 infection control nurses, 5 public health officers, and 2 community health officers. Three face-to-face workshops were conducted for the participating personnel to spread knowledge on concepts and methods of collaborative quality improvement, applying collaborative quality improvement in determining preventive measures to prevent loss to follow-up among newly diagnosed pulmonary TB patients, to present causes of loss to follow up from data of participating hospitals. The experts gave information on preventive measures to prevent loss to follow up from literature reviews. Brainstorming, opinion and experience sharing, and reviewing problems and factors related to loss to follow-up sessions were conducted to conclude causes of loss to follow-up among newly diagnosed pulmonary TB patients of hospitals in each region, determine concrete and appropriate measures for solving each important cause of loss to follow-up according to patients’ characteristics, practical, and sustainable for implementation. Project responsible personnel developed a guideline for prevention of loss to follow-up among newly diagnosed pulmonary TB patients using the conclusions from the project workshops and literature reviewed. The outcome of the project was a “Guideline for prevention of loss to follow-up among newly diagnosed pulmonary tuberculosis patients”, which consisted of 3 parts: Chapter 1) Knowledge on Tuberculosis for hospital personnel which included TB pathogen, mode of transmission of TB, risks of TB infection, latent tuberculous infection and TB, factors affecting TB treatment and prevention of TB transmission by patients, environment, personnel and social, TB drug, side effects and caution in TB drug treatment, storage of TB drug, surveillance of side effects of TB drug, caring for patients with side effects of TB drug, education of newly diagnosed pulmonary TB patients, and counseling. Chapter 2) Self- care recommendation for TB patients which included details on TB drug administration, follow-up, prevention of TB transmission, general health care, and nutrition. and Chapter 3) Guideline for caring of newly diagnosed pulmonary TB patients to prevent loss to follow-up consisted of patient preparedness, TB patient education, creating awareness for continuous treatment, encouragement, empowerment, stress management, right to treatment, follow-up and referral system, networking, collaboration and resources both inside and outside hospitals.