Background: The anti-epidermal growth factor receptor (EGFR) drugs cetuximab and panitumumab are currently reimbursed when administered during the first and subsequent lines of treatment of patients in the Czech Republic with metastatic colorectal cancer (mCRC). Because cetuximab and panitumumab do not show significant differences in efficacy, their choice may be dependent on cost. This retrospective study analyzed the costs of first-line treatment with cetuximab and panitumumab of patients with mCRC and wild type KRAS, as well as evaluated the correlations between costs and effectiveness, as determined by progression-free survival (PFS) and overall survival (OS). Patients and methods: This analysis included 51 patients with mCRC and confirmed wild type KRAS treated at the comprehensive cancer centre in the Czech Republic between November 2011 and April 2018. Of these 51 patients, 22 were treated with cetuximab and 29 with panitumumab. Direct medical costs (medications, clinical examinations and procedures, and hospitalization) were evaluated from the initiation of treatment with anti-EGFR drug to disease progression and death. Mean follow-up was 21 months in the cetuximab group and 19 months in the panitumumab group. Results: Reimbursement for anti-EGFR drugs until disease progression accounted for 71% (mean, 964,288 CZK per patient) of total costs in the cetuximab group and 77% (mean, 1,003,229 CZK per patient) of total costs in the panitumumab group, with median PFS in these two groups being 10.7 months and 8.1 months, respectively. Reimbursement of expensive center drugs from the start of anti-EGFR treatment to patient death accounted for 55% of total costs in the cetuximab group (mean, 1,752,702 CZK per patient) and 63% of total costs in the panitumumab group (mean, 1,596,919 CZK per patient), with median OS in these two groups being 20.2 months and 19.8 months, respectively. No significant between-group differences in clinical effectiveness and costs of treatment were observed (p > 0.05 each). Conclusion: Reimbursement for biological agents is the most expensive item in the first-line treatment of mCRC patients with wild type KRAS, both to disease progression and death. The clinical effectiveness and costs of cetuximab and panitumumab did not differ significantly.