['Study objectives, included determination of: (i) associations between radiologic and pathologic responses of colorectal cancer liver metastases (CRCLM) to chemotherapy; and (ii) whether CRCLM histopathology is associated with recurrence free survival (RFS) after resection among patients not treated with pre-operative chemotherapy (untreated).', 'Demographics, clinicopathologic characteristics, and outcomes among patients who underwent CRCLM resection from 2007 to 2014 were reviewed. Tumor regression grade (TRG) of 1-2 and 4-5 depict low and high proportions of viable tumor relative to fibrosis, respectively.', 'Of 138 patients, 84 (60.9%) were treated with pre-operative chemotherapy. In these patients, there was no difference in proportions with TRG 1-2 among those with verses without radiologic response (26.9% vs. 18.8%, P\u2009=\u20090.393). TRG 1-2 was associated with superior RFS on univariable (median 15 vs. 6 months, P\u2009<\u20090.001) and multivariable (P\u2009=\u20090.005) analyses. Radiologic response was not associated with RFS. Among untreated patients (n\u2009=\u200954), TRG 4-5 was associated with poor RFS on univariable (median 44 vs. 15 months, P\u2009=\u20090.011) and multivariable (P\u2009=\u20090.012) analyses.'] Does tumor histopathology predict outcomes after resection of colorectal cancer liver metastases treated with and without pre-operative chemotherapy?