The aim of our retrospective cohort study is to analyze the persistence rates in relation to antiosteoporotic drugs using administrative databases in the Campania Region. Patients, aged ≥40 years, were included if at least one prescription for any antiosteoporotic drugs had been filled in between January 1, 2009 and December 31, 2009. Overall, 37,594 patients were incident users of antiosteoporotic drugs. Among them, 15,978 patients had undergone spot-therapies. A total of 2,618 (14.1%) were classified as switchers. Switching rates were highest for patients taking Alendronate 18.9 or Strontium Ranelate 15.0 and lower for patients taking Ibandronate 12.8 or Risedronate 10.8. In the overall population, 33.5% of subjects were still on therapy after 6 months. At 1 year, persistence rates were: Ibandronate 21.6%, Risedronate 15.8%, Alendronate + Vitamin D 15.7%, Raloxifene 14.3%, Alendronate 12.6% and Strontium Ranelate 5.0%.