Abstract Texture is an important parameter which influences on the quality and acceptability of yoghurts. The utilize of stabilizers in yoghurt manufacturing has become a prevalent application to improve the textural properties of yoghurts. In this context, guar gum obtained from Cyamopsis tetragonolobus is generally used as a natural stabilizer for its thickening and gelling properties. Accordingly, this study evaluated the use of chia seed mucilage as an alternative to guar gum to improve the textural properties of yoghurt. This study focused on the effect of using chia seed mucilage (CSM) and guar gum (GG) at 1, 2, and 3% concentrations on the textural and microstructural characteristics of yoghurts. The results of fortifications with CSM and GG on the physicochemical, sensory, and antioxidative properties of yoghurts were also evaluated. Compared to GG, CSM provided higher antioxidant activity which improved with increasing concentrations of CSM. An enhancement was observed in textural properties of yoghurts containing CSM and GG, but CSM concentrations up to 2% gave better effect on firmness. Besides, the microstructure of yoghurt was enhanced depending on the increase in CSM and GG amounts. No negative effect was determined on the sensory properties of the samples by CSM and GG additions. The results showed that CSM can be used in set-type yoghurt production as an alternative stabilizer by improving firmness and consistency and reducing syneresis. Furthermore, its use is suitable for industrial yoghurt production with regards to sensorial properties.