ObjectivesImplementation of smoking cessation care (SCC) guidelines is suboptimal. This mixed-method study evaluated a two-component implementation strategy for the revised Dutch multidisciplinary tobacco dependence treatment guideline, which consisted of the provision of text-messages and summary-sheets tailored to specific healthcare professional (HCP) groups, i.e., gynecologists, midwives, pediatricians, practice nurses and respiratory nurses. DesignObservational study with baseline (T1), intermediate (2-months, T2) and follow-up (8-months, T3) survey measurements, and interviews between T2 and T3. MethodData were collected December 2016–January 2018. Three hundred-ten, 228, and 174 HCPs completed T1, T1/T2, and T1/T2/T3, respectively, and 32 HCPs were interviewed. We examined reach, feasibility and acceptability of the implementation strategy; whether baseline factors related to HCP’s strategy evaluation; change in implementation outcomes over time (i.e., knowledge, intentions to use the guideline, satisfaction with own SCC delivery, and provision of quit-advice); and whether baseline factors related to change in implementation outcomes. ResultsText-messages had good reach, and text-messages and summary-sheets were evaluated positively on feasibility and acceptability. Results showed improvements over time in tested knowledge (assessed through false/true statements) and self-reported knowledge about SCC, as well as satisfaction with own SCC delivery. Provision of quit advice showed an improvement among pediatricians only. Improvements in knowledge were stronger among non-smoking HCPs, and HCPs with lower skills and self-efficacy at baseline. ConclusionsGuideline implementation often does not occur spontaneously. Guideline implementation may be facilitated by providing text-messages and summary-sheets to HCPs. Text-messages may be more beneficial if tailored to the individual HCP.