Objective: To explore how the See-and-Treat concept can be applied in primary care and its effect on volume and productivity. Design: An explanatory single-case study design with a mixed methods approach and presented according to the SQUIRE 2.0 guidelines. Setting: A publicly-funded, private primary care provider within the Stockholm County, which caters to a diverse patient population in terms of ethnicity, religion, socioeconomic status and care needs. Participants: CEO, center manager, four physicians, two licensed practical nurses, one medical secretary and one lab assistant. Intervention: A See-and-Treat unit was established to offer same-day service for acute unplanned visits. Standardized patient symptom forms were created that allowed patients to self-triage and then enter into a streamlined care process consisting of a quick diagnostic lab and a physician visit. Main Outcome Measures: Volume, productivity, staff perceptions and patient satisfaction were measured through data on number and type of contacts per 1000 listed patients, visits per physician, observations, interviews and a questionnaire. Results: A significant decrease in the acute and total number of visits, a continued trend of diminishing telephone contacts, and a non-significant increase in physician productivity. Patients were very satisfied, and staff perceived an improved quality of care. Conclusions: See-and-Treat appears to be a viable approach for a specific primary care patient segment interested in acute same-day-service. Opening up access and standardizing care made it possible to efficiently address these needs and engage patients. © 2019 The Author(s) 2019. Published by Oxford University Press in association with the International Society for Quality in Health Care.