This article focuses on the outcomes at 1 year post-treatment of a naturalistic evaluation of services provided through the Takiwasi Centre, an accredited Peruvian therapeutic community offering an ayahuasca-assisted, integrative treatment program for addiction rehabilitation. Participants (n = 52) completed structured interviews and a battery of validated instruments. Outcome measures included the Addiction Severity Index (Version 5), the Beck Anxiety and Depression Inventories, the World Health Organization Quality of Life Brief Version (WHOQOL-BREF), and the World Health Organization Quality of Life Spiritual Religious and Personal Belief (WHOQOL-SRPB) scale. Likert rating scales were used to assess perceived importance and significance of different aspects of the program and overall participant satisfaction. The group change from baseline to the 1-year follow-up was significant and in the anticipated direction for alcohol and drug use severity, depression and anxiety, and some dimensions of quality of life. There was considerable individual variation in outcomes and treatment duration. The majority of participants rated all aspects of the program as important, including the spiritual and therapeutic significance of the ayahuasca experience, which was rated as very significant. Based on the positive 1-year outcomes, and within the limitations of an uncontrolled observational study design, the findings suggest promise for the effectiveness of the use of ayahuasca in a multifactorial treatment context for individuals with significant treatment histories, high levels of comorbidity, and treatment motivation. Results highlight considerable variation in individual experience that merit in-depth qualitative analysis. Implications for ayahuasca-assisted and other psychedelic-assisted treatment alternatives are discussed.