The aim of this study is to determine serum CCL23 levels and their clinical associations in patients with systemic sclerosis (SSc). Serum CCL23 levels were examined by ELISA in 66 patients with SSc, 20 patients with systemic lupus erythematosus, 20 patients with dermatomyositis, and 33 healthy individuals. Serum CCL23 levels were elevated in SSc patients (389.1 ± 199.2 pg/mL) compared with healthy individuals (94.1 ± 85.6 pg/mL; P < 0.001) and patients with systemic lupus erythematosus (43.4 ± 39.3 pg/mL; P < 0.001) or dermatomyositis (132.1 ± 104.5 pg/mL; P < 0.001). Among SSc patients, there were no differences in serum CCL23 levels between those with limited cutaneous SSc and those with diffuse cutaneous SSc. SSc patients with elevated CCL23 levels were found to have shorter disease duration than those with normal CCL23 levels (P < 0.001). Furthermore, raised CCL23 levels were associated with a higher frequency of pulmonary arterial hypertension (P < 0.05). The results show that serum CCL23 level was increased in the early phase of SSc. CCL23 could be associated with induction of SSc and as such would be a serologically useful marker for disease activity.