Objective: To explore the effect of a family-centred, information-motivation-behavioural skills (IMB)-based intervention on breastfeeding attitudes among women with gestational diabetes mellitus (GDM). Methods: 84 GDM patients were divided into two groups according to different nursing methods. The observation group(n=42)received usual care plus the IMB family-centred programme, and the control group (n =42)received usual care only. Breastfeeding knowledge, motivation, attitude and glycaemic indices were compared, together with exclusive breastfeeding rates on postpartum day3 and at1,3and6months. Results: After the intervention, scores on the breastfeeding knowledge, motivation and attitude scales were higher in the observation group than those in the control group (P <0.05). Fasting glucose, 2-h postprandial glucose and HbA1c were lower in the observation group(P<0.05). Exclusive breastfeeding rates at all four timepoints were higher in the observation group (P <0.05). Conclusion: The IMB-based family-centred intervention improves breastfeeding knowledge, motivation and attitudes, facilitates glycaemic control and increases exclusive breastfeeding rates in women with GDM.