The rotation-curve of NGC 3504 was obtained from measures of the Ha, H , [N ii] X 6583, X 6548, [Oiii] X 5007, [5 ii] X 6731, X 6716 emission lines on spectra taken at the prime focus of the 82-inch telescope and from the H emission line on spectra taken at the Cassegrain focus. The rotation-curve extends out to about 50" from the center, though there is a gap between about 6" and 25" from the center where no emission regions are present. This means that the form of the rotation-curve and hence the mass distribution cannot be very well determined. The rotation-curve in the nuclear region is linear. The orientation of the galaxy has been determined from the shape of the inner bright region in which rotation is seen. The outer arms might suggest that the system is face-on, but the observations of rotation contradict this. These outer arms may be elliptical or not coplanar with the main body. Mass estimates for the nucleus and the whole galaxy have been estimated by making an assumption about the rotation- curve. We conclude that the mass lies in the range 2.5 x 100 Mo «M< 9>C 100 Mo. The mass-to-light ratio (photographic) is about 0.7, if a mass of 9 x 100 is assumed. With a=mass of 9 x 100 Mo, M/L could be slightly higher than this, since the outer arms were included in the measured luminosity, while no determination of the mass of them can be made.