Background <p>Navigation programs support people and families by addressing barriers to care and mitigating physical, psychosocial, and practical challenges. While navigation programs are increasingly recognized within European healthcare systems, evidence on implementation strategies for scale-up across settings such as a Train-the-Trainer program remains limited and rarely comprehensively evaluated. This study evaluates a Train-the-Trainer program developed within the EU NAVIGATE project as an implementation strategy to deliver a navigation program for older people with cancer living at home in six European countries.</p> Methods <p>The multi-method evaluation follows the four levels of the Kirkpatrick model. Levels 1 and 2 (Reaction and Learning) were assessed via questionnaires completed by trainers; Level 3 (Behavior) through weekly diaries and group interviews with (international) trainers; and Level 4 (Results) through questionnaires completed by navigators and the intervention beneficiaries (older people with cancer). Quantitative data were analyzed descriptively; qualitative data were analyzed using qualitative content or narrative analysis.</p> Results <p>At Levels 1 and 2, trainers (<i>n</i> = 11) rated the program as highly useful on a five-point Likert-scale ranging from 1 to 5 (median = 5, IQR = 0.75), reporting strong alignment with their role, clear understanding of the program, and high confidence (median scores 4–5). At Level 3, according to weekly diaries and group interviews, trainers applied the competencies they learned. Successes included positive navigator feedback and training adaptation. Challenges included workload and time constraints, limited team collaboration, and difficulties adapting materials. The ability to contextually adapt the training was facilitated by applying the competencies. At Level 4, reported high levels of overall understanding and confidence following the training, with median scores of 4 (IQR = 1) for both outcomes on a 5-point Likert scale, with highest scores reported for addressing quality of life, and lower scores for supporting technology use. Older people with cancer (<i>n</i> = 101) responded that navigators generally demonstrated the intended competencies with median scores ranging from 1 (IQR = 2) to 5 (IQR = 1) on a 5-point Likert scale.</p> Conclusion <p>Findings demonstrate the potential of training to implement a navigation program to improve long-term age-appropriate support, emphasize the importance of contextually adapting to local settings, and underline the need for further research to enhance the transferability of navigation programs across diverse health systems.</p> Trial registration <p>Clinicaltrials.gov: identifier NCT06110312 (2023/10/31).</p>