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Chlorophyll meters have been used to estimate leaf chlorophyll content, and therefore nitrogen (N) status and fertilization requirements for several crops. However, until now C₄ forage grasses have not been investigated in this regard. A field study was conducted in 1995 and 1996 to evaluate the potential of chlorophyll (SPAD) meter readings to determine switchgrass N concentration and herbage yield. Meter readings were taken on the top most fully expanded leaves of switchgrass grown on a free draining sandy clay loam soil (St Bernard, Typic Hapludalf) fertilized at 0, 75, or 150 kg N ha^‐1. The switchgrass was either cut at the end of the season or every four or six weeks. Herbage N concentration in uncut stands declined with time while SPAD readings increased to a mid‐season maximum, beyond which they declined rapidly. The relationship between N concentration and SPAD readings was linear (r²=0.62 …