Abstract: Titanium dioxide particles having a mean primary particle size of less than 100 nm, each of said particles being substantially coated with phospholipid are disclosed. The phospholipid is preferably selected from phosphatidyl cholines, phosphatidyl ethanolamines, phosphatidyl serines, phosphatidyl inositols and mixtures thereof, in particular lecithin. Phospholipid-coated titanium dioxide particles may be incorporated into oil-in-water and water-in-oil emulsions to provide novel sunscreen compositions with excellent ultraviolet screening efficiency, long term stability and water-resistant properties.