Introduction: Normal size of mesenteric lymph nodes has not been well-evaluated, as these lymph nodes are small but may be seen frequently in computed tomography(CT). The aim of this study is to determine the prevalence of mesenteric lymph nodes at root of mesentery and mesentery itself. Method and Materials: This is a cross-sectional study on traumatic patients with normal multi-detector computed tomography(MDCT) referred to Al-Zahra Hospital in2014-2016. largest short axis of Lymph nodes was recorded. Their location was divided to 3groups of mesenteric root, peripheral mesentery and mesentery of right lower quadrant(RLQ). Size and number of lymph nodes in terms of locations were recorded. Number of more than 6 nodes in a position was defined as cluster nodes. Data were analyzed using SPSS-20. P-value of Results: 400 traumatic patients underwent MDCT-scanning. The mean age of these patients was 36.6±13.4 years. The number of lymph nodes was less than3 in 49.3%, 52.5% and52.2%; 3-6 in 45.8%, 42.8% and 42.8%; more than 6 in 5%, 4.8% and4.8% of central, peripheral and RLQ mesentery, respectively. The average size of largest central, peripheral and RLQ lymph nodes were 4.53±1.33, 4.37±1.68 and 4.37±1.68respectively(P-value=0.64). Largest size of short axis in patients with cluster lymph nodes was significantly more than non-cluster nodes(P-value Conclusion: Mean size of mesenteric lymph nodes was similar to previous study but the largest nodes were considerably larger. Also largest short axis of cluster nodes were significantly more than non-cluster ones.