Background: LS is among the most common hereditary cancer (CA) syndromes, underlying 3% cases of colorectal CA (CRC) and 8% of CRC < 50 yrs. Pts with LS have a very high lifetime risk of CRC, which has been shown to be decreased by intensive colonoscopy (COLO) surveillance. However, interval LS CRCs can still develop, and adjunctive therapies like ASA have been recognized for their chemoprev benefits, with 35% risk reduction associated with sustained ( > 2 yrs) use. Existing data are scarce on uptake of ASA chemoprev in LS pts, as well as pt-level factors that may impact uptake. Methods: PREVENTLynch recruited LS participants in the Fox Chase Cancer Center (FCCC) Risk Registry, who were invited to complete a one-time e-survey after providing informed consent (1/2020-6/2020; IRB 20-8014). Demographic/personal/familial CA history were collected. Inconvenience (INC), side effects (SEs), prevention reassurance (PR), and likelihood of recommending (LoR) available and emerging CA prevention modalities were measured on 9-point scales (low = 1 vs high = 9). Results: 116 LS pts completed the survey. Mean age was 53 yrs [range 23-76 ]. 24.7% (33/116) reported being on ASA, with 24.2% (8/33) taking it for an unrelated cardiac indication. 96.6% (112/116) had completed COLO, with 60.5% getting annual screening and 39.5% getting screening in 2-3 yrs. No significant difference was noted among ASA users and non-users based on age, race and underlying genetic LS subtype. A majority of pts (61.6%) were on ASA 81 mg/day, while 24.3% and 12% reported taking 325 and 650 mg/day, respectively. LS pts both taking and not taking ASA perceived it to be convenient (mean INC: 1.18 ASA users vs 2.11 non-users, p = 0.01). Concern for SEs was lower in ASA users than non-users (mean 1.09 vs 2.30, p = 0.003) while PR of the protective benefits was higher in the ASA users (mean PR 5.94 vs 3.23, p < 0.001). When comparing ASA to COLO, COLO was seen as more INC than ASA by both ASA users and non-users (mean COLO INC 3.0 and 3.1, p = 0.0001 and 0.017 compared to ASA INC, respectively). ASA users were more likely to recommend ASA to others (8.13 vs 4.09, p < 0.001). Conclusions: ASA uptake is low among LS pts. ASA is perceived as a favorable modality of chemoprev in only a fraction of LS pts, with perceived SEs and low PR as barriers to uptake. There is a critical need to address negative perceptions of chemoprev in LS patients as more options are developed.