Recent data indicated that statin therapy may fail to reduce the incidence of coronary events in patients concomitantly using β blockers. The aim of the present study was to examine whether the concomitant use of β blockers would modify the anti-inflammatory action of statins. Changes in C-reactive protein (CRP) between days 1 and 5 after myocardial infarction were evaluated in 189 patients treated with simvastatin alone (S), β blockers alone (B; propranolol or metoprolol), S + B, or neither of these 2 medications (N) in a prospective observational cohort. At baseline, median CRP was lower in the S group (0.40 mg/dl, interquartile range 0.1 to 0.6) than the other groups (B: 0.6 mg/dl, interquartile range 0.4 to 1.6; S + B: 0.5 mg/dl, interquartile range 0.3 to 1.2; and N: 0.6 mg/dl, interquartile range 0.2 to 1.5). By day 5, median CRP was 1.3 mg/dl (interquartile range 0.7 to 2.6), 4.3 (interquartile range 1.6 to 8.8), 4.6 (interquartile range 2.8 to 9.5), and 4.4 (interquartile range 1.9 to 9.9) for the S, B, S + B, and N groups, respectively. After adjusting for log_e baseline CRP, the difference in log_e CRP between days 1 and 5 was significantly lower in the S group compared with the B (−0.74 ± 0.23 [SE], p = 0.001) or S + B group (−0.99 ± 0.20 [SE], p <0.0001). The significance remained after adjustment for age, gender, and baseline CRP. There was no significant difference in change in CRP between the SB and B groups. In conclusion, the present study confirmed the anti-inflammatory action of statins and showed that concomitant use of β blockers may significantly attenuate this effect.