InAsxP1−x/InP strained multiple quantum wells with strain as high as 2.5% were grown by gas‐source molecular beam epitaxy. Successful control of the arsenic composition over a wide range was achieved by two different growth techniques. Structural and optical studies, such as high‐resolution x‐ray rocking curve, cross‐sectional transmission electron microscopy, photoluminescence, and absorption measurement, indicate that we have obtained high quality multiple quantum wells that are suitable for optoelectronic applications.