This article explores mothers’ narratives of changing home smoking behaviours after participating in an intervention (Reducing Families’ Exposure to Smoking in the Home [REFRESH]) aimed at reducing families’ exposure to secondhand smoke (SHS) in homes in Scotland. An analysis of qualitative findings illuminates quantitative changes in levels of SHS exposure. Prospective quantitative and qualitative data were drawn from 21 smoking mothers with at least one child under 6 years. Quantitative change was measured by home air quality, i.e. fine particulate matter <2.5¿µg (PM2.5). These measurements guided the organization of mothers into categories of change (smoke-free home at baseline [SFB], smoke-free home at final, some change and no change [NC]). Qualitative data from 17 mothers with non-SFB were analysed thematically within and across these categories. Three comparative case studies illustrate the varying changes made, barriers to change and how mothers valued such changes. The outcomes varied post-intervention, with homes smoke-free, partially smoke-free or making NC. The changes in home smoking behaviour were incremental, yet beneficial to reducing SHS exposure, and related to the nature of the restrictions and personal circumstances in the home pre-intervention. Across all change categories, mothers valued the changes they had made and expressed an intention to increase the changes.