The role of upfront primary tumor resection (PTR) in patients with unresectable metastatic col-orectal cancer (CRC) without severe symptoms remains controversial. We retrospectively ana-lyzed the role of PTR in overall survival (OS) in different subgroups. Among 331 patients diag-nosed with synchronous metastatic CRC between 2010 and 2020, 223 were analyzed. The PTR group (n = 42) showed better performance (p = 0.038); higher frequencies of right-sided origin (p = 0.014), T4 stage (p = 0.005), M1a stage (p = 0.015), and <2 organ metastases (p = 0.002); and re-ceived fewer targeted agents (p < 0.001) than the chemotherapy group (n = 181). The PTR group showed longer OS (20.5 versus 14.0 months, p = 0.016), but PTR was marginally related to OS in multivariate analysis (p = 0.060). Male sex (p = 0.022), good performance status (p = 0.07), left-sided tumor (p = 0.069), low serum carcinoembryonic antigen level (p = 0.092), T3 stage (p = 0.029), M1a stage (p = 0.025), <2 organ metastases (p = 0.017), and administration of targeted agents, especially bevacizumab (p = 0.024), were related to survival benefit after PTR. Upfront PTR should be considered when selecting patients with favorable prognoses for bevacizumab administration.