Stationary processes of different physical nature (oscillations, thermal conductivity, diffusion, electrostatics, etc.) are described by equations of elliptic type. In particular, some models, such as hydro and gas dynamics, consider elliptic equations. In this paper, we study a nonlocal boundary value problem with the Poincaré condition for an equation of the elliptic-hyperbolic type of the second kind, i.e. for an equation where the line of degeneration is a characteristic. Refs.: 8 titles.Keywords: nonlocal boundary value problem, Poincaré conditions, equations of elliptic - hyperbolic type, equations of the second kind.