First stage nozzle airfoils have internal core profiles substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table I wherein X, Y and Z values are in inches. The X and Y values are distances which, when connected by smooth continuing arcs, define internal core profile sections at each radial distance Z. The profile sections at each distance Z are joined smoothly to one another to form a complete internal core profile. The X, Y and Z distances may be scalable as a function of the same constant or number to provide a scaled-up or scaled-down internal core profile. The nominal internal core profile given by the X, Y and Z distances lies within an envelope of ±0.030 inches in directions normal to any internal core surface location.