The present invention provides a method of making a leaflet assembly, the leaflet assembly thus made and a prosthetic valve. The leaflet assembly can take a first form wherein the valve is open and a second form wherein the valve is closed, the valve comprising a leaflet assembly having at least one leaflet attached to a supporting element, the leaflet having a free margin that can move between a first position wherein the valve takes the first form and a second position wherein the valve takes the second form, the method comprising providing a textile structure, and forming the leaflet assembly from the textile structure, such that a selvedge of the textile structure forms the free margin of the leaflet, wherein the textile structure is made by weaving warp and fill threads into a two-layer woven fabric having two stacked and interconnected layers, the two layers having selvedges at one longitudinal edge, and wherein forming the leaflet assembly comprises connecting two lateral edges of a single piece of the fabric to make a substantially tubular structure wherein the inner layer forms the leaflet and the outer layer forms the supporting element. With this method a prosthetic valve can be made with little process variability and errors, and resulting in a valve with high reliability and durability.