Introduction: Expression of PDL-1 in tumor cells is one of the mechanisms by which tumors suppress immune surveillance, enabling them to invade and metastasize. Antibodies targeting PD1 and PDL-1 are currently being used in clinical trials and showed significant benefit in a variety of tumor types. In one large series of CRC, high PDL-1 expression was found to correlate inversely with lymph node metastasis, in contrast with what is reported in other solid tumors (Droeser et al 2013); in that study PDL-1 was scored manually using visual analog scale of immunohistochemically (IHC) stained sections. The aim of this study was to investigate the relationship between PDL-1 expression in CRC with nodal status using quantitative image analysis. Methods: Sections of 70 samples of CRC were stained by IHC using specific antibodies to PDL-1 and CD8. The level of PDL-1 expression was determined using the image analysis software OTMIAS and associated PDL-1 standard. The number of CD8 positive lymphocytes was determined by direct counting using a grid and a cell counter. Statistical analysis was performed using Prism statistical analysis software. Results: CRC with high levels of PDL-1 expression (>70% of tumor cells with > 20 units of PDL-1 per cell) were more likely to be associated with lymph node metastasis (7 of 13 or 54%) than CRC with lower PDL-1 expression (14 of 57 or 25%) (p < 0.05). There was no significant association between PDL-1 expression and depth of tumor invasion. The mean number of CD8 positive lymphocytes in CRC with high PDL-1 expression was less (18) than that with lower PDL-1 (24) although the difference did not reach statistical significant (p=0.06). Conclusion: Our finding, using quantitative image analysis, show that high PDL-1 levels in CRC are associated with increased incidence of lymph node metastasis, similar to what have been reported for other solid tumors. Therefore, patients with CRC expressing high levels of PDL-1 may benefit from related targeted therapy.