Inflammation and cancer are tightly linked. This study tests the hypothesis that an inflammatory score based on plasma levels of C-reactive protein (CRP) and fibrinogen and whole blood leukocyte count is associated with risk of colorectal, lung, breast and prostate cancer. A score ranging from none through three elevated biomarkers was constructed in 84,000 individuals from the Danish general population. During a median follow-up time of 4.8 years, 4,081 incident cancers occurred. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) of incident cancer. Multifactor-adjusted HRs for colorectal cancer were 1.28 (95% CI, 1.01 to 1.62), 1.79 (95% CI, 1.41 to 2.27) and 2.18 (95% CI, 1.67 to 2.86) for individuals with elevated levels of one, two and three inflammatory biomarkers compared to individuals with none elevated biomarkers. A similar stepwise increasing risk was observed for lung and breast cancer with HRs of 3.03 (95% CI, 2.25 to 4.08) and 1.42 (95% CI, 1.11 to 1.80) for three versus none elevated biomarkers. HRs were highest within the first years of follow-up. Absolute 5-year risk of lung cancer was 7.8 (95% CI, 6.1 to 10)% among older smokers with three elevated biomarkers compared to 3.8 (95% CI, 2.6 to 5.6)% among those with none elevated biomarkers. In conclusion, simultaneously elevated CRP, fibrinogen and leukocyte count are associated with an increased risk of colorectal, lung and breast cancer. Cancer as a promoter of inflammation may be more likely to account for our findings than low-grade inflammation promoting cancer development.