Very little is known about baseline predictors of acute ayahuasca effects. This aim of this study is to explore demographic and psychological characteristics as predictors of acute spiritual, psychological, and physical effects of ayahuasca. Method: Data include baseline/pre-retreat (BL) and one-week post-retreat follow-up (T2) from an ongoing longitudinal prospective cohort study of people attending an ayahuasca retreat in Costa Rica (N=53; Mean age=40.15, SD=10.93; female=60.4%; White=86.8%). Descriptive analyses, Pearson correlations, and paired samples t-tests were conducted for this preliminary data analysis. Results: Identifying as non-Hispanic (r=.29; p=.034) and being employed full-time (r=-.28; p=.040) were correlated with higher ratings of acute emotional breakthrough. Next, having an intention that included treatment of a mental health condition was significantly correlated with higher levels of psychological insight (r=.34; p=.012) at T2, and those with an intention for having a spiritual experience at BL was significantly correlated with higher levels of mystical experience (r=.43; p=.001) and psychological insight (r=.52; p<.001) at T2. Third, higher levels of expecting improvements from the ayahuasca experience at BL, was positively correlated with acute mystical experience (r=.35; p=.010), psychological insight (r=.30; p=.031), and emotional breakthrough (r=.32; p=.018), and greater openness to experiences was positively correlated with intensity of mystical experience (r=.31; p=.023), and emotional breakthrough (r=.29; p=.036). Conclusions: These findings suggest several important baseline features which might predict the acute effects of ayahuasca in ceremonial retreat setting. Specifically, one’s intention for the experience, expectancy about drug effects, and level of openness to experience all emerged as significant predictors. Future research should explore the importance of these features in laboratory studies using rigorous controlled designs.