Franco-Mendes was a prolific writer. Among his dramas, most of them written in poetic form, his best-known work, Gemul Atalyah (Amsterdam, 1770), is reminiscent of Racine's tragedy Athalie. Many of his biographies of famous Sephardi Jews were published in Ha-Me'assef (1785ff.), and posthumously in Ha-Maggid (1860–66); some of his poems were also published in Ha-Me'assef, but the bulk is still in manuscript. Nir-le-David, responsa from the years 1735 to 1792, was partly published in She'elot u-Teshuvot of the yeshivah Ets Hayyim. Sefer Tikkunim is a critical work on some of the writings of Maimonides. His works on the Portuguese and Spanish Jews of Amsterdam (still in manuscript) are of historical value.