The guitar has a seemingly endless number of incarnations, no doubt due to the instruments lengthy history and wide geographical use. One such incarnation is the Portuguese guitar, a plucked instrument with twelve strings strung in six courses of two strings each. The instrument is noticeably smaller than a standard classical guitar, has a distinctive tuning mechanism (more on this later) and its body is more rounded, or "pear-shaped." These characteristics have to do with the fact that Portuguese guitar is actually a cittern, a close cousin of the guitar. The cittern was a very popular instrument in Europe during the Renaissance Period, valued for its relatively inexpensive price and easy of play. A specific cittern, the English "guitar," is thought to be the direct ancestor of the modern Portuguese guitar.

The Portuguese guitar as such can be traced back to the early 19th century. During that century, the instrument was produced in a variety of shapes and sizes in accordance with regional aesthetic preferences. It was not until the first half of the 20th century that Portuguese guitars were standardized. At that time, the instrument was refined into two distinct models: the Lisboa guitar and the Coimbra guitar. These two versions of the Portuguese guitar are still in use today and both retain the overall appearance of the earlier instruments.

While both types of Portuguese guitars are undeniably variations of the same instrument, each has certain unmistakable characteristics. The Lisboa has a larger soundboard and invariably possesses a scroll-shaped headstock. The Coimbra, on the other hand, has a teardrop-shaped headstock, a narrower neck and smaller string spacing. The Lisboa usually has a scale of 440 mm and a bell-like sound; the Coimbra has an average scale of 480 mm and an accentuated bass sound in accordance with its larger scale.

To play the Portuguese guitar, a musician utilizes a method of fingerpicking during which only the fingernails are used; the flesh of the fingers never comes into contact with the strings. In modern times, in an effort to save their fingernails, artists usually use fingerpicks that can be attached to the ends of the fingers. These fingerpicks are most commonly plastic, although the shell of the endangered tortoise was once popular and such picks can still be found. The musician uses only his thumb and index finger, resting the other fingers below the strings and against the soundboard. The fingerpicking technique of the Portuguese guitar is called "dedillo" or "dedilho," which roughly translates as "to know thoroughly." In this context, it may be taken to mean that the string is plucked thoroughly.

The Portuguese guitar is most commonly associated with fado, a Portuguese musical genre that can be traced back to the 1820s; this was approximately the same time that the Portuguese guitar became popular. Like its instrument, fado can be divided into two varieties, Lisboa and Coimbra. The former style is the more popular of the two, but the latter is held to be more refined. Fado, which translates roughly as "fate," is a plaintive musical genre, the subject of which is often nostalgia. Fado performances invariably utilize the music of the Portuguese guitar.