Attenuation of the immune response to surgery, as demonstrated with the laparoscopic approach to cholecystectomy, has potential benefits in patients undergoing laparoscopic colonic resection for malignancy. We aimed to study the perioperative immune response in patients undergoing laparoscopically assisted and open surgery for colorectal cancer. This study involved 23 patients undergoing laparoscopically assisted (n = 13) and open surgery (n = 10). Interleukin-6 (IL-6) C-reactive protein (CRP), the total lymphocyte count, and the CD3, CD4, CD8, CD16, and CD19 lymphocyte subpopulations were assayed preoperatively and at 4, 8, 10, 24, 48, and 168 h postoperatively. Significant rises in IL-6 and CRP were demonstrated within 4 and 24 h, respectively (p < 0.001) in both groups. However, no significant difference between the groups was seen. Significant decreases in total lymphocyte count and all T cell subsets were demonstrated in both groups, beginning at 4 h (p < 0.01). However, no significant difference between the groups was seen. All parameters, excluding CRP, had returned to baseline by 7 days postoperatively in both groups. Patients with malignancy exhibit significant perioperative immune disturbance with laparoscopically assisted and open surgery. The current data do not provide justification for the laparoscopically assisted approach on grounds of immune preservation.