The viola d'amore shares many features of the viol family. Like viols, it has a flat back and intricately carved head at the top of the peg box, but unlike viols, the head occurs often with blindfolded eyes to represent love , and its sound-holes are commonly in the shape of a flaming sword (suggesting a Middle Eastern influence in its development). It is unfretted, and played much like a violin, being held horizontally under the chin. It is about the same size as the modern viola.

The viola d'amore usually has six or seven playing strings, which are sounded by drawing a bow across them, just as with a violin. In addition, it has an equal number of sympathetic strings located below the main strings and the fingerboard which are not played directly but vibrate in sympathy with the notes played. A common variation is six playing strings, and instruments exist with as many as fourteen sympathetic strings alone. Despite the fact that the sympathetic strings are now thought of as the most characteristic element of the instrument, early forms of the instrument almost uniformly lacked them. The first unambiguous reference to a viola d'amore without sympathetic strings does not occur until the 1730s. Both the types continued to be built and played through the 18th century.

Largely thanks to the sympathetic strings, the viola d'amore has a particularly sweet and warm sound.

Leopold Mozart, writing in his Versuch einer gründlichen Violinschule, said that the instrument sounded "especially charming in the stillness of the evening."

The first known mention of the name 'viol d'amore' appeared in John Evelyn's diary (20 November, 1679):

"for its swetenesse & novelty the Viol d'Amore of 5 wyre-strings, plaid on with a bow, being but an ordinary violin, play'd on Lyra way by a German, than which I never heard a sweeter Instrument or more surprizing..."