We have measured interstellar scintillations of two binary pulsars (1855+09 and 1913+16) to determine their transverse velocities at numerous points in their orbits. Combining transverse velocities with radial velocities derived from Doppler shifts, one can (in principle) determine a binary system’s proper motion and orbital inclination, and the bulk velocity of the scattering material along the line of sight. With our present observations we cannot unambiguously determine these quantities but we are able to place interesting limits on some of them. In particular, we find that the orbital inclination of 1855+09 is larger (≳70°), a finding which strongly constrains the mass of the pulsar’s companion. The bulk velcoity of scattering material seems to be less than 25 km s−1.