Background Physical activity on prescription (PAP) is a recommended method in Swedish and European primary healthcare, yet implementation remains inconsistent. This study explored barriers and strategies for strengthening PAP use in a region with low prescription rates, from the perspective of healthcare personnel and managers. Methods A mixed-methods study with an explanatory sequential design was conducted (2024) in a geographically dispersed Swedish region. Digital surveys with healthcare personnel and managers (n = 93) were analysed using uni-, bi- and multivariate analyses, followed by semistructured interviews (n = 14) analysed with qualitative content analysis guided by Normalization Process Theory (NPT). Results The survey was completed by 75 healthcare personnel and 18 managers. Most healthcare personnel (84%, n = 58/69) reported providing basic PA advice regularly, but only 16% (n = 12/74) prescribed PAPs. Physiotherapists prescribed PAP more often than other personnel (32%, n = 8/25 vs. 8%, n = 4/47; p = .018), and this remained significant in adjusted analyses (OR 4.0, 95% CI 1.01-15.83). Documentation of PAP components according to the Classification of Health Care Interventions (KV & Aring;) was generally low. Physiotherapists more often reported high or very high competence in counselling compared with other healthcare personnel (100%, n = 27/27 vs. 72%, n = 34/47; p = .003), prescribing PAP (74%, n = 20/27 vs. 36%, n = 17/47; p = .003), and follow-up (78%, n = 21/27 vs. 32%, n = 15/47; p < .001). Female healthcare personnel expressed stronger trust in PAP evidence than males (p = .013). Few personnel had received PAP training (38%, n = 28/74), and most were unaware of existing guidelines (81%, n = 61/75). Time constraints (53%, n = 41/75) and lack of guidelines (48%, n = 38/75) were the most common barriers, with older healthcare personnel (>= 46 years) more likely to report time constraints (OR 3.6, CI 1.27-10.16). Managers more often highlighted unclear purpose of PAPs and patient reluctance, whereas personnel emphasised lack of training and managerial prioritisation. Despite these differing perspectives, 69% (n = 50/72) of healthcare personnel and 75% (n = 12/16) of managers endorsed increasing PA counselling. Conclusions Strong interest in PAPs indicates favourable conditions for sustainable implementation if legitimacy-building education (coherence), tailored resources and training (cognitive participation), multilevel leadership commitment (collective action), and coordination for monitoring (reflexive monitoring) are secured. These are necessary strategic investments, transferable beyond Sweden to systems facing PAP implementation challenges.