Near Infrared Spectroscopy (NIRS) has been successful in the determination of protein in forages and grains. Therefore, its expansion into the determination of nitrogen (N) and starch in cotton leaves was explored. Calibration of NIRS spectra of cotton leaves with standard laboratory procedures produced equations that were utilized, not only on same season leaf samples (1991) but also on leaf samples collected over a three‐year period (1990–1992). Samples from each of the collection years should improve equation bias and coefficient of determination.