OBJECTIVES: No adequate data are available about the epidemiology of spinal fusion surgery and its economic impact. The objective of this analysis was to assess the epidemiologic and economic burden of arthrodesis from a large population based-study. METHODS: Lombardy Region includes around 9.9 million individuals. The study population was identified through a data warehouse (DENALI), which matches with a probabilistic linkage demographic, clinical and economic data of different Healthcare Administrative databases. The study population was made by all subjects who, during the period January 2001–December 2010, underwent a spinal fusion surgery identified by one of the following codes ICD9-CM: 81.04 81.05, 81.06, 81.07 and 81.08. The first procedure was used as index event. We estimated the incidence of first spinal fusion surgery, the population and surgery characteristics and the healthcare costs from the National Health Service’s perspective.  RESULTS: During the study period, 17,772 (53.2% female) spinal fusion surgeries were detected. The results showed an increasing patients’ average age during the time period considered. The incidence rate of interventions increased from 12.6 to 19.1 per 100,000 person-year in the observational period between 2001 and 2006. During the last 4 years of observation, the incidence was above 20.0 per 100,000 person-year. The average hospital length of stay reported for the index event was 17.1 days in the 2001 and decreased until 11.0 days in the 2004. The average cost of the spinal fusion surgery increased during the observational period, from € 4.381 up to € 9,388.  CONCLUSIONS: The study showed an increasing incidence of spinal fusion surgery and costs from 2001 to 2010 in the Italian Lombardy Region. These results can be used to better understand the epidemiological and economic burden of these types of interventions, and help to optimize the resources available considering the different surgical procedures available today.