Clinical guidelines are systematically developed statements designed to help practitioners and patients make decisions regarding the appropriate health care for specific circumstances. Guidelines are based on the scientific evidence on therapeutic interventions. The first asthma guidelines were published in the mid 1980s when asthma became a recognized public health problem in many countries. The Global Initiative on Asthma (GINA) was launched in 1995 as a collaborative effort between the NHLBI and the World Health Organization (WHO). The first edition was opinion-based but updates were evidence-based. A new update of the GINA guidelines was recently available and it is based on the control of the disease. Asthma guidelines are prepared to stimulate the implementation of practical guidelines in order to reduce the global burden of asthma. Although asthma guidelines may not be perfect, they appear to be the best vehicle available to assist primary care physicians and patients to receive the best possible care of asthma.