OBJECTIVES To estimate the costs and benefits of Timing Pharmaceutical Intervention (TPI) through an example of asthma in Alberta, Canada. METHODS We included changes in direct health care and lost productivity costs, and Health Related Quality of Life (HRQOL) among Alberta's asthmatic adults (18 years and over) in a one year time period. Health care costs and benefits were estimated through the effects of TPI on drug uses and health care utilization patterns, including hospital days, ER visits and physician visits. Productivity and HRQOL benefits were estimated through the effects of TPI on the number of symptom free days (SFDs) of patients at age 18–64 and at all adult ages respectively. Health care utilization rates, unit costs, SFDs days and HRQOL index scores from the literature were used for analyses. The costs were adjusted to 2006 Canadian dollar value. RESULTS In a year, in addition to a saving of $0.2–$0.3 million in health care costs, TPI on asthma generates a benefit of $12–$19 million in terms of improved productivity and 22–29 quality adjusted life years in terms of improved HLQOL. CONCLUSIONS The costing model provides us with a rough indication of the economic impact of TPI. It is not expected that TPI will always yield net savings in terms of health care costs for all chronic conditions. This will depend on specific diseases and the cost effectiveness of the intervention among the target population. However, other benefits, such as improved HRQOL and productivity, should be considered in the decision making.