Background: Recent studies show that obesity plays a major role in causing chronic inflammation by producing several inflammatory cytokines. On the other hand, there is limited research focusing on the effect of obesity in recurrent breast cancer treatments. Therefore, we set out to clarify the impact of obesity related inflammation by Neutrophil to Lymphocyte ratio (N/L ratio) in recurrent breast cancer treatment. Methods: From January 2005 to December 2014, 93 patients with recurrent breast cancer after surgery were included. World Health Organization body mass index (BMI) classification was used for evaluating the degree of obesity. Muscle mass amount was also analyzed. Lumber skeletal muscle index (LSMI, cm²/m²) was generated by standardizing each patient’s muscle area (m²) at the third lumber vertebrae level in axial CT data. Less than 50m² in LSMI was defined as pre-sarcopenia. N/L ratio was calculated from the laboratory data, and more than 3.0 was defined as high N/L group. Results: Patient background showed there were 20 overweight patients and 2 obese patients. Twenty-eight cases had pre-sarcopenia. In univariate analysis, N/L ratio had no significant differences among BMI categories. However, triple negative (TN) type demonstrated significantly high N/L ratio compared to other subtypes (p < 0.05). LMSI had significant negative correlation to N/L ratio (p < 0.05). In survival analysis, Overweight/Obese group showed significantly shorter OS (p < 0.05). High N/L ratio group also showed similar results (p < 0.05). When stratified by intrinsic subtypes, TN type demonstrated significantly shorter OS (p < 0.05). Additionally, Overweight/Obese groups in TN type had notably shorter OS (p < 0.05). In multivariate analysis, subtype and N/L ratio were independently related to OS (Hazard ratio: 3.3 in TN type, 2.9 in High NL ratio group). Conclusions: Present study did not show any significant relationship between obesity and chronic inflammation in recurrent breast cancer setting. On the contrary, intrinsic subtype was significantly related to inflammation, leading to pre-sarcopenia and worse OS. Whether obesity promotes inflammation in TN type needs more investigation.