Using the expected income model, this paper explores the determinants of population migration in Colombia. The basic hypothesis is that differential economic opportunities by department play a central role in determining the spatial allocation of the population. Recently published data from the 1973 Population Census are used to test whether the rates of lifetime migration into Colombia's 23 departments are associated with departmental labor market conditions. Male and female population movements are considered, both separately and together. For both sexes, the empirical results sustain the validity of the economic model of migration in the Colombian context.