615 Background: Optimal timing from colorectal surgery to initiation of adjuvant chemotherapy is between 4 to 6 weeks based on recent data. In MCRC, therapeutic benefits of ctx are frequently calculated from start of treatment. We investigated whether the interval between dx and commencement of ctx influences overall survival (OS) in patients (pts) with MCRC. Methods: Pts with CRC were identified from the institutional database. Inclusion criteria were MCRC and receipt of ctx. Clinicopathologic details were collected. Intervals from histologic dx to ctx were calculated. Analyses were based on receipt of ctx within 4 weeks (w), 5-8w and > 8w of dx. Survival was compared between groups. OS was presented as hazard ratio (HR) with associated p value. Results: Between 2003 and 2013, 123 pts were identified, where 58 pts receive ctx within 4w, 38 within 5-8w and 27 > 8w. Median OS (mOS) was 8.7, 15.7 and 13.7 months (mths) respectively. Improvement in OS was noted in pts treated 5-8w and >8w compared to within 4w (HR 0.53, 0.45; p=<0.01, <0.01). Surgical resection of the primary was noted in 14% of pts receiving ctx in 4w, 45% between 5-8w and 70% > 8w and mOS amongst these groups were 19.5, 16.3, and 22.1 mths respectively versus 6.5, 10.5 and 8.9 mths in similar groups without surgery. Improved OS in resected pts is noted in when treated 5-8w and > 8w compared to 4w (HR 0.76, 0.72 p= 0.55, 0.46) with no difference in OS between groups treated at 5-8w and > 8 w (HR 1.06, p= 0.85). Univariate and multivariate analyses for 5 variables are described in the Table, two of which are statistically significant on multivariate analyses. Conclusions: Our data did not suggest a detrimental effect on OS from ctx delay and the lack of survival benefit from early ctx might be due to a number of confounding variables as described above. [Table: see text]