  Hipparcos geometrical parallaxes allowed us to calibrate the Cepheid
Period-Luminosity relation and to compute the true distance moduli of 17
galaxies. Among these 17 galaxies, we selected those which generated type Ia
Supernovae (SNe Ia). We found NGC 5253, parent galaxy of 1895B and 1972E, IC
4182 and NGC 4536 parents of 1937C and 1981B, respectively. We used the
available B-band photometry to determine the peak brightness of these four SNe
Ia. We obtained <M_{B}(MAX)> = -19.65 \pm 0.09.
  Then, we built a sample of 57 SNe Ia in order to plot the Hubble diagram and
determine its zero-point. Our result (ZP_{B} = -3.16 \pm 0.10) is in agreement
with other determinations and allows us to derive the following Hubble constant
: Ho = 50 \pm 3 (internal) km.s^-1.Mpc^-1.
