Objective To evaluate the association between red blood cell (RBC) transfusion leading to necrotizing enterocolitis (NEC) within 48 h, known as transfusion-associated necrotizing enterocolitis (TANEC). Methods A nested case-control study using historical data was conducted in the neonatal intensive care unit of Songklanagarind Hospital, Thailand. All very low birth weight (VLBW) infants delivered between November 2009 and July 2016 were enrolled. The infants were identified as RBC transfusion received and NEC developed. Logistic regression was used to evaluate risk factors for transfusion and the association between RBC transfusion and NEC. Results Four hundred and forty-four VLBW infants were enrolled in the study. The median (interquartile range) gestational age was 29 (27, 31) wk. The overall incidence of NEC was 13%. Three (5.2%) of the NEC infants had TANEC. The infants who received RBC transfusion had a lower gestational age [odds ratio, OR 0.64; 95% confidence interval (95%CI) 0.57, 0.73, p < 0.001] and were more likely to have pneumonia (OR 9.86; 95%CI 5.02, 19.35, p < 0.001) or to have received H 2 blocker (OR 2.92; 95%CI 1.73, 4.93, p < 0.001). The ORs (95% CI) after adjusting for confounders, the association between RBC transfusion and NEC for transfusions ≤2 d, >2 to 4 d, and > 4 to 6 d prior to NEC were 1.83 (0.41, 8.16; p = 0.43), 1.7 (0.26, 11.16; p = 0.58) and 1.19 (0.31, 4.62; p = 0.80) respectively. Conclusions After controlling of confounders, no evidence of association was found between RBC transfusion and TANEC.