Scaling up opioid agonist therapies (OAT) is the most effective strategy to control combined HIV and opioid epidemics, especially in Eastern Europe and Central Asia (EECA), where HIV incidence and mortality continue to increase. Patient concerns about OAT, however, have undermined scale-up. The objective of this study is to understand Ukrainian opioid use disorder patient preferences about OAT to guide the development of an evidence-informed decision aid for clinical decision-making. We conducted a conjoint-based choice (CBC) survey. Participants were asked to about their preferences relating to 7 attributes of OAT (cost, dosing frequency, concerns about withdrawal symptoms, adverse side effects, improvements in quality of life, precipitation of withdrawal and legislative requirements to be registered as a drug dependent person) and 20 attribute levels for receiving OAT under differing potential treatment constraints. Data were analyzed using Hierarchical Bayesian models. Using respondent-driven sampling and random sampling, we recruited 2,028 people who inject drugs with opioid use disorder. Relative importance (RIS) and partial-worth utility scores (PWUS) were used to assess preferences for attributes and thresholds within each attribute. Cost and dosing frequency were the most important attributes (RIS = 39.2% and RIS = 25.2%, respectively) to potential patients, followed by concerns about withdrawal symptoms (RIS = 10.8%), adverse side effects (RIS = 9.0%), quality-of-life improvement (RIS = 7.5%), precipitation of euphoria (5.2%) and requirement to be registered as a drug- dependent person (RIS = 3.1%). The monthly cost-threshold for willingness-to-pay was 1,900 UAH ($70 USD). In Ukraine, where both governmental and private OAT clinics have emerged and provide markedly different delivery strategies, preferences are mostly driven by out-of-pocket expenses, despite many patients being willing to pay for OAT. Programmatic demands (flexibility and ease of acquiring medications) remain an important consideration while for a minority, clinical concerns about withdrawal symptoms, adverse side effects and OAT impact on life play a smaller role.