Malnutrition has been identified as an independent risk factor for surgical site infection (SSI). Guidelines advise that malnourished patients should be counselled and strategies implemented to improve nutritional intake prior to surgery. However, the current total hip replacement (THR) literature lacks of prospective clinical trials. The aim of this study was to investigate if the probability of acute SSI following THR is related to whether or not the patient had pre-operative low transferrin levels, low albumin levels and/or low total lymphocyte cell count (TLC). All patients receiving THR in a single Institution during a 2-year period were assessed prospectively for presence of malnutrition and SSI within 3 months after unilateral THR. Malnutrition was defined as albumin <35 g/L, transferrin <2g/L or TLC < 1.5 E9/L. Patients with previous infection(s) were excluded. Multivariate analysis included gender, age, BMI, diabetes, and immunocompromised status. 478 patients with a complete dataset were included in the study; 137 (27.6%) had at least one low value of transferrin, TLC or albumin. SSI was recorded in 22 hips (4.6%) including 6 deep infections. Hypoalbuminaemia (RR, 1.28, p=0.5), low transferrin (RR, 1.39, p=0.4) or low TLC (RR, 1, p=0.1) were not associated with SSI. Multivariate analysis showed no association between abnormal blood tests suggesting malnutrition, BMI and SSI. Only BMI had a low p value for association with SSI (p=0.006). This study shows that abnormal blood tests associated with malnutrition are not an independent risk factor for SSI in THR.