INTRODUCTION: The clinical benefit of extended lymphadenectomy for synchronous extraregional lymph node metastasis, such as para-aortic lymph node (PALN) metastasis in colorectal cancer, remains highly controversial. AIM: To evaluate the clinical benefit of PALN dissection in colorectal cancer patients with synchronous PALN metastasis with or without multiorgan metastases. METHODS: Thirty-six patients with pathologically positive PALN metastasis below the renal veins who underwent concurrent PALN dissection and primary colorectal cancer resection from January 1984 through September 2011 at the National Cancer Center Hospital in Tokyo, Japan, were included in this retrospective cohort study. We examined 5-year recurrence-free survival (RFS) rates in patient groups depending on the number of nodes involved (≤2 and ≥3 nodes) and on the presence or absence of other organ involvement (M1a and M1b,c categories in TNM staging). RESULTS: The 5-year RFS rate was significantly different depending on the number of metastatic PALNs (42.1 and 0.6% for PALN ≤2 and ≥3, respectively, p = 0.01). The 5-year RFS rate was significantly better in patients in the M1a category than in patients in the M1b and M1c categories (27.6 and 0.0%, respectively, p < 0.01). Twenty-nine patients (80.6%) experienced recurrence after PALN dissection. Postoperative complications were seen in 14 (38.9%) patients. CONCLUSION: PALN dissection below the renal veins for patients with isolated PALN metastasis with 2 or fewer involved PALNs may be effective in improving prognosis in colorectal cancer.