  A study on the intermediate polar EX Hya is presented, based on simultaneous
photometry and high dispersion spectroscopic observations, during four
consecutive nights. The strong photometric modulation related to with the
67-min spin period of the primary star is clearly present, as well as the
narrow eclipses associated to the orbital modulation. Since our eclipse timings
have been obtained almost 91,000 cycles since the last reported observations,
we present new linear ephemeris, although we cannot rule out a sinusoidal
variation suggested by previous authors. The system mainly shows double-peaked
H$\alpha$, H$\beta$ and HeI $\lambda$5876 \AA emission lines. From the profile
of the H$\alpha$ line, we find two components; one with a steep rise and
velocities not larger than $\sim$1000 km s$^{-1}$ and another broader component
extending up to $\sim$2000 km s$^{-1}$, which we interpret as coming mainly
from the inner disc. A strong and variable hotspot is found and a stream-like
structure is seen at times. We show that the best solution correspond to $K_1 =
58 \pm 5$ km s$^{-1}$ from H$\alpha$, from the two emission components, which
are both in phase with the orbital modulation. We remark on a peculiar effect
in the radial velocity curve around phase zero, which could be interpreted as a
Rositter-MacLaughlin-like effect, which has been taken into account before
deriving $K_1$. This value is compatible with the values found in
high-resolution both in the ultraviolet and X-ray. We find: $M_{1} = 0.78 \pm
0.03$ M$_{\odot}$, $ M_{2} = 0.10 \pm 0.02$ M$_{\odot}$ and $a = 0.67 \pm 0.01$
R$_{\odot}$. Doppler Tomography has been applied, to construct six Doppler
tomograms for single orbital cycles spanning the four days of observations to
support our conclusions. Our results indicate that EX Hya has a well formed
disc and that the magnetosphere should extend only to about
$3.75\,R_{\rm{WD}}$.
