The relation between serum inflammatory protein levels and cognitive performance was investigated in a healthy population. Individuals were tested during 6 years of follow-up. Serum concentrations of 10 inflammatory proteins were correlated to cognitive speed (Letter-Digit Coding Test, LDCT), attention and information processing (Stroop) and memory (Word Learning). Haptoglobin levels at baseline correlated negatively with cognitive performance on the Stroop and Word Learning Recall test over the 6 years follow-up period. C-reactive protein (CRP) levels at baseline correlated negatively with performance on the Word Learning tests over the 6 years follow-up period. Thus, relatively high concentrations of haptoglobin and C-reactive protein may be indicative for impaired cognitive performance.