  In this paper we present and analyze new CCD $UBVRI$ photometry down to
$V\approx$21 in the region of the young open cluster Trumpler~15, located in
the Carina spiral feature. The cluster is rather compact and has a core radius
of about 2$^{\prime}$, which translates in about 1 pc at the distance of the
cluster. We provide the first CCD investigation and update its fundamental
parameters. We identify 90 candidate photometric members on the base of the
position in the color-color and color-magnitude diagrams. This sample allows us
to obtain a distance of 2.4$\pm$0.3 kpc from the Sun and a reddening
E$(B-V)$=0.52$\pm0.07$. We confirm that the cluster is young, and fix a upper
limit of 6 million yrs to its age . In addition, we draw the attention on the
lower part of the Main Sequence (MS) suggesting that some stars can be in
contracting phase and on a gap in the MS, that we show to be a real feature,
the $B1-B5$ gap found in other young open clusters. We finally study in details
the extinction toward Trumpler~15 concluding that it is normal and suggesting a
value of 2.89$\pm$0.19 for the ratio of total to selective absorption $R_V$.\
