A study by electron microscopy of coconut palm (Cocos nucifera L.) leaves from trees infected by the Cape St. Paul wilt (Kaincope) disease of West Africa was carried out. Samples were obtained during the dry season (Dec.–Jan.) and fixed immediately upon removal from the trees in buffered glutaraldehyde. Further processing for electron microscopy was carried out within a week. No virus particles, mycoplasma-like organisms (MLO), fungi, or bacteria were detected in thin sections. Crystalline or paracrystalline accumulations of electron-opaque granules, approximately 5.5–6 nm in diameter, were observed in disintegrated chloroplasts of mesophyll cells. Based upon their morphological characteristics, formation of the slightly curved, “fingerprint” arrays or linear rows running parallel, and the visualization of electron-opaque cores in unstained preparations, the granules were identified as phytoferritin particles.