[AIMS - Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular abnormalities, fibrosis, inflammatory changes, and late stage atrophy with obliterative vasculopathy. Clinically it has two distinct subtypes, limited (lcSSc) and diffuse cutaneous systemic sclerosis (dcSSc). Carnitine is an essential metabolite with ester forming capability. We investigated the possible relationship between carnitine metabolism and systemic sclerosis, stratified by disease subgroups. PATIENTS AND METHODS - We performed comparative measurements of carnitine profile in 107 systemic sclerosis patients (78 lcSSc and 29 dcSSc) and 47 healthy controls using triple quadrupol ESI mass spectrometry. RESULTS - C2-, C3-, C8-, C10:1- and C10-carnitine ester levels were moderately decreased in the serum of the patients, while C5- and C6-carnitine ester concentrations increased in both types of the disease compared with controls; as a summary, these changes altogether led to reduced total carnitine ester concentrations. Free carnitine level remained unaffected. CONCLUSIONS - These results show that both types of SSc have a moderate influence on shortand medium chain carnitine ester metabolism, but likely do not affect the quantity of the free carnitine reserves.]