OBJECTIVES: The objective was to evaluate the impact of Herpes Zoster (HZ) as associated diagnosis on hospitalizations for an other main health problem, using 3 evaluation criteria: length of stay, number of death and cost from the national health insurance perspective. METHODS: The hospitalizations of people aged 50 years and more were selected from the French national hospital database (PMSI) 2011 using ICD 10 diagnosis code: HZ (B02*) in associated diagnosis (DAS), and excluding codes of  immunosuppressive conditions (D8* or B20*-B24*). The 5 main categories of diseases leading to hospitalization distribution allowed us to select, in decreasing order of importance: circulatory (I0*-I5* & I7*-I9*), respiratory (J0*-J9*), digestive (K0*-K9*), osteo-articular systems (M0*-M9*), and diabetes (E1*).  For each of the 5 categories, a retrospective case-control has been realized. The cases are defined by hospitalizations with HZ in DAS and controls were hospitalizations without HZ in DAS matched on age and sex to the cases. Statistical non parametric analyses (Wilcoxon-Mann-Whitney) in each of the five categories have been realized to evaluate the difference in length of stay, death rate, and cost. RESULTS: In each of the five categories, cases presented a statistically significant length of stay compared to the controls. Median differences varying of 3 days for osteo-articular system (+50%) to 6 days for digestive system (+300%). None difference in the death rates has been observed. The study also demonstrated a statistically significant cost of cases compared to the controls median differences varying of 857€ for circulatory system (+25%), 922€ for osteo-articular system (+26%), 945€ for respiratory system (+26%), 987€ for diabetes (+39%), and 2011€ for digestive system (+126%). CONCLUSIONS: When present as an associated diagnosis in hospitalizations of people 50+ for other medical reasons, HZ significantly increases the length of stay at hospital and subsequent economic burden for the French health system.