The surface morphology of GaAs thin films grown by molecular beam epitaxy on (110) substrates misoriented towards (111)A is studied using atomic force microscopy in a wide range of growth temperatures. Two regimes of unstable growth with distinct growth morphologies are identified. At substrate temperatures between 450 and 500°C, macrosteps are created with step edges oriented along [11̄0] or [11̄2]. Above 550°C, GaAs (110) vicinal surfaces become unstable towards transverse meandering, and a ripple pattern morphology with ridges running along the [001] direction is formed. We attribute the two types of growth instabilities observed to differences in attachment kinetics of adatoms to surface steps at different As surface coverages.