The most reliable and accurate portrait to date is that provided by Cervantes himself in his prologue to the Novelas ejemplares (1613):

"He whom you see here, of aquiline features, with chestnut hair, a smooth forehead, with sparkling eyes, and a nose arched, though well-proportioned,--a beard of silver which, not twenty years since, was of gold,--great moustaches, a small mouth, the teeth of no account, for he has but six of them, and they in bad condition and worse arranged, for they do not hold correspondence one with another; the body, between two extremes, neither great nor little; the complexion bright, rather white than brown; somewhat heavy in the shoulders--this, I say, is the aspect of the author of "La Galatea" and "Don Quixote of La Mancha," and composed the "Voyage of Parnassus," . . commonly known as Miguel de Cervantes Saavedra."