Abstract Purpose: Procalcitonin (PCT) is accepted to be a relevant prognostic marker for the development of clinical complications in multiple trauma patients. Therefore, a prospective cohort study was conducted to investigate whether polymorphisms in the calcitonin ( CALCA) gene are associated with PCT levels and posttraumatic complications. Methods: During a 14 day observation period, blood samples were drawn once daily for systemic PCT concentrations in multiple trauma patients (Injury Severity Score >16). For analysis of allele frequencies, genotype distribution and PCT concentrations polytraumatized patients were separated, according to the development of SIRS, sepsis, septic shock, ARDS, MODS and mortality. Furthermore, association between CALCA polymorphisms and PCT plasma concentrations was assessed. Results: One hundred thirty seven patients with a mean ISS of 29.2 ± 12.1 were included. When trauma patients were grouped according to different posttraumatic complications no association with CALCA SNPs was observed. Additionally, no association was found between CALCA polymorphisms and systemic PCT levels. Conclusion: CALCA polymorphisms are unlikely to influence clinical outcome in polytraumatized patients. Effects of microbial and inflammatory mediators, as well as other risk factors (gender, age, etc.) seem to have a more significant influence on the transcriptional regulation of CALCA and on PCT plasma concentrations than CALCA polymorphisms.