This paper presents the in situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene (DCPD) to create microcapsules for self-healing materials. The microcapsules, with diameters ranging from 10 to 1000 μm, were prepared by polymerizing urea and formaldehyde in an oil-in-water emulsion. The agitation rate was found to be a key factor in controlling the mean diameter of the microcapsules, with a linear relationship observed between log(mean diameter) and log(agitation rate). The microcapsules exhibit a smooth inner membrane and a rough, porous outer surface composed of agglomerated urea-formaldehyde nanoparticles. The surface morphology and shell wall thickness were investigated using optical and electron microscopy. The microcapsules have a high fill content of 83-92 wt% DCPD and a shell thickness of 160-220 nm, making them suitable for self-healing applications. The study also explores methods to control the surface morphology, such as maintaining constant pH and increasing the interfacial area between the core and water, which can enhance mechanical adhesion and performance in self-healing applications.This paper presents the in situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene (DCPD) to create microcapsules for self-healing materials. The microcapsules, with diameters ranging from 10 to 1000 μm, were prepared by polymerizing urea and formaldehyde in an oil-in-water emulsion. The agitation rate was found to be a key factor in controlling the mean diameter of the microcapsules, with a linear relationship observed between log(mean diameter) and log(agitation rate). The microcapsules exhibit a smooth inner membrane and a rough, porous outer surface composed of agglomerated urea-formaldehyde nanoparticles. The surface morphology and shell wall thickness were investigated using optical and electron microscopy. The microcapsules have a high fill content of 83-92 wt% DCPD and a shell thickness of 160-220 nm, making them suitable for self-healing applications. The study also explores methods to control the surface morphology, such as maintaining constant pH and increasing the interfacial area between the core and water, which can enhance mechanical adhesion and performance in self-healing applications.