  The bright southern star Delta Vel is a multiple system comprising at least
three stars. Its brightest component, Delta Vel A, was identified in 2000 as
one of the brightest eclipsing system in the sky. Its eclipses are easily
observable with the unaided eye, a remarkable property shared only by Algol,
Beta Aur, Alpha CrB and Psi Cen. We determined dynamical masses from a
combination of spectroscopy, high-precision astrometry of the orbits of Aab-B
and Aa-Ab using adaptive optics (VLT/NACO) and optical interferometry
(VLTI/AMBER). The main eclipsing component is a pair of A-type stars in rapid
rotation. We modeled the photometric and radial velocity measurements of the
eclipsing pair Aa-Ab using a self consistent method based on physical
parameters (mass, radius, luminosity, rotational velocity). From this modeling,
we derive the fundamental parameters of the eclipsing stars with a typical
accuracy of 1%. We find that they have similar masses, respectively 2.43 +/-
0.02 and 2.27 +/- 0.02 Msun. The physical parameters of the tertiary component
(Delta Vel B) are also derived, although to a lower accuracy, as well as the
parallax of the system, 39.8 +/- 0.4 mas. This value is in satisfactory
agreement (-1.2 sigma) with the Hipparcos parallax of the system (pi_Hip =40.5
+/- 0.4 mas).
