BackgroundLow adherence to triage after positive screening is a widespread problem for cervical cancer screening programs in Low- and Middle-income Countries. Adherence to cytology-based triage can be challenging, especially among women with self-collected tests. SMS-based interventions are accepted by women and can increase screening uptake. The ATICA study was an effectiveness-implementation hybrid type I trial, combining a cluster randomized controlled trial (RCT) with a mixed-methods implementation evaluation involving quantitative and qualitative methods. Although the RCT provided evidence regarding the effectiveness of the SMS-based intervention, less is known about its acceptability, relevance, and usefulness from the women´s perspective.MethodsWe carried out a cross-sectional study based on a structured questionnaire among HPV-positive women who were enrolled in ATICA's intervention group. We measured acceptability, appropriateness, and message content comprehension. Also, we evaluated if the SMS message was considered a cue to encourage women to pick up their HPV test results and promote the triage.ResultsWe interviewed 370 HPV-positive women. Acceptability of SMS messages among women who had received at least one message was high (97%). We found high levels of agreement in all appropriateness dimensions. More than 77% of women showed high comprehension of the content. Among women who received at least one SMS message, 76% went to the health center to pick up their results. Among those who got their results, 90% reported that the SMS message had influenced them to go. We found no significant differences in acceptability, appropriateness or message comprehension between women who adhered to triage and those who did not adhere after receiving the SMS messages.ConclusionThe intervention was highly acceptable, and women reported SMS was an appropriate channel to be informed about HPV test results availability. SMS was also a useful cue to go to the health center to pick up results. The implementation did not encounter barriers associated with the SMS message itself, suggesting the existence of other obstacles to triage adherence. Our results support the RCT findings that scaling up SMS is a highly acceptable intervention to promote cervical screening triage adherence.