Background <p>Patient engagement in research enriches study design, conduct, and dissemination by integrating lived experiences of patients into the research process. Although patient engagement is becoming more popular in clinical research settings, it remains comparatively rare in preclinical (i.e. laboratory based) research. To explore this gap, we conducted an interview study to understand how researchers and patients have implemented patient engagement in this area, focusing on the challenges and benefits of their approach.</p> Methods <p>We conducted semi-structured interviews of patients (<i>n</i> = 15) and researchers (<i>n</i> = 14) with previous preclinical patient engagement experience. Interviews were transcribed and reviewed using an inductive, thematic content analysis, which allowed for bottom-up analysis of interview data. Our team identified, reviewed and refined emerging themes. Our team members include preclinical, clinical and patient engagement researchers and patient partners, which allowed for various perspectives to contribute to the final interpretation of the findings and drafting of the manuscript.</p> Results <p>We identified five themes. Theme 1: Researchers and patients highlighted the necessity to <i>adopt a thoughtful and tailored approach</i> for each preclinical engagement initiative. This includes taking time to cultivate personal relationships and co-developing engagement activities to meet patient and researcher preferences and needs. Theme 2: Clear communication was deemed critical, suggesting the need for a <i>clear and shared vocabulary</i> without technical jargon. Theme 3: V<i>aried goals for engagement in preclinical research</i> between researchers and patients were underscored, indicating the need to discuss aims and motivations early and often as well as to co-develop mutually beneficial strategies. Theme 4: Researchers and patients also discussed how their communities require <i>a better understanding of the value of preclinical patient engagement</i>. This could be fostered through education and illustrative case examples. Theme 5: Finally, a <i>shift in research culture</i> was deemed necessary and called for stronger institutional support, efficient channels to connect preclinical researchers and patients, as well as initiatives that recognize and champion preclinical patient engagement.</p> Conclusion <p>Our study identified five common themes in preclinical patient engagement which can help the research community facilitate meaningful engagement of patients in preclinical laboratory research.</p>