Marcello composed and published several sets of concerti (including six under the title La cetra) and some cantatas, often under the pseudonym Eterio Stinfalico. Although his works are performed extremely infrequently today, he is regarded as a very competent composer. Johann Sebastian Bach arranged an oboe concerto in D minor by him for harpsichord (BWV 974).
Alessandro's brother was Benedetto Marcello, also a composer.