Documentation of normal growth in late adolescence has been limited to a few studies using largely white participants. Annual growth rates of 668 high school girls who had already achieved menarche were determined for stature, sitting height, and knee height measured using the Knee Height Measuring Device (KHMD), an instrument with superior reliability. The sample was 61.4% white, 16.8% Puerto Rican, 15.7% African American, and 6.1% girls of other ethnic backgrounds. Median growth rate was 1.5 cm/year for stature, 1.1 cm/year for sitting height, and 2.7 mm/year for knee height in the first full year after menarche, and >80% of all girls grew in at least one dimension. Growth in stature (β₯1 cm) continued for 64% of girls 1 full year after menarche and for 31% of girls 2 years after menarche, and growth in knee height (β₯1 mm) continued in >45% of girls up to 5 completed years past menarche. Whites, African Americans, and Puerto Ricans showed small but significant differences in amounts of postmenarcheal growth in the dimensions measured. African-American girls grew less in stature and sitting height than other groups, whereas Puerto Rican girls grew significantly more in sitting height and significantly less in knee height than other ethnic groups. These findings demonstrate that, as documented in other studies of postmenarcheal growth, there is substantial growth after menarche in most girls. The most sensitive measures indicate that small amounts of growth persist >5 years after menarche. Appreciation of this phenomenon needs to be communicated to clinicians who generally assume that growth ceases at/or just after menarche. Β© 1996 Wiley-Liss, Inc.