We combine Hα imaging and broad-band optical and NIR imaging over the face of the barred galaxy NGC 3359, obtained within the BARS program on the Canary Island telescopes. From the Hα image we have determined the positions, fluxes, and diameters of a total of 547 Hii regions, and computed their luminosity function, whose slope is within the range of those of morphologically similar galaxies found in the literature. We have gone on to quantify other statistical properties, such as the diameter distribution and the number density of the Hii regions, deduced the global Hα surface density distribution and disc scale length and to derive some physical parameters of individual Hii regions. Measuring the integrated diffuse Hα flux for the galaxy, we have compared this with the computed ionizing flux escaping from the population of density-bounded Hii regions, showing that the latter can give rise to the diffuse component. We present complementary images in broad-band, and in colours, which give clues to the star formation and dust distributions, as well as the underlying stellar mass distribution. The bar, which shows obvious symptoms of youth, exhibits striking differences in mean position angle as a function of wavelength in the optical and near IR mass component.