Background: Adipocytokines have been proposed as factors mediating associations between obesity and inflammation in patients with colorectal cancer (CRC). Thus, the aim of this study was to determine the clinical relationships between blood concentrations of leptin (LEP), adiponectin (ADP), and tumor necrosis factor alpha (TNF-alpha) and the outcomes measured in patients with CRC undergoing surgery. Patients and Methods: History, body composition, and blood concentrations of LEP, ADP, and TNF-alpha were determined in 107 patients undergoing surgery due to CRC. The patients were followed up for 619.72 ± 371.65 days. Results: Compared to patients with stage II CRC, individuals with clinical stage I CRC had significantly lower ADP and higher TNF-alpha blood concentrations. We found significant correlations between the clinical stage of CRC (early vs. localized vs. metastatic) and the following: crude blood ADP concentration (R = 0.25; p = 0.015), ADP-to-TNF-alpha ratio (R = 0.31; p = 0.002), and ADP when indexed to body surface area (R = 0.25; p = 0.008) and to fat mass (R = 0.25; p = 0.016). The risk of death during the long-term follow-up period was independently related to the clinical stage of CRC, impairment of the patient’s functional status, and higher blood carcinoembryonic antigen concentration. In Kaplan-Meier survival analysis, patients with blood LEP concentrations adjusted to a visceral adipose tissue score of ≥0.47 had a significantly better likelihood of surviving than their counterparts. Conclusions: In patients with CRC undergoing surgery, blood ADP and TNF-alpha concentrations were associated with the clinical stage of the cancer, likelihood of radical tumor excision, occurrence of nonsurgical postoperative complications, and long-term survival, which suggests the role of dysregulation in the endocrine function of adipose tissue in response to the neoplasmatic process.