Successful application of interfacial engineering for the preparation of cross-linked epoxy microspheres containing thermally polymerizable cardanol-based benzoxazine (Bz-C) monomer in the core is demonstrated. Bz-C is facilely synthesized by Mannich type condensation of cardanol (a by-product of cashew nut industry) and aniline with formaldehyde under solventless conditions. The encapsulation process relies on the preferential reaction of polydimethylsiloxane immiscible epoxy resin and amine-based hardener to form a cross-linked spherical shell at the interface. The microcapsule dimensions and core content could be tailored by modulating the operating parameters, particularly stirring speed and Bz-C: epoxy ratio. Spherical microcapsules with a core content of ∼37\% were obtained when the reaction was carried out at 600 rpm, while maintaining the reaction medium at 70°C with Bz-C: epoxy ratio of 2.3: 1. The simplicity and versatility of the present methodology are the forte of this technique, which widens the scope for large-scale application of benzoxazines in the field of temperature triggered healing. © 2015 Wiley Periodicals, Inc.