  We present a new catalogue of galaxy triplets derived from the Sloan Digital
Sky Survey Data Release 7. The identification of systems was performed
considering galaxies brighter than M_r=-20.5 and imposing constraints over the
projected distances, radial velocity differences of neighbouring galaxies and
isolation. To improve the identification of triplets we employed a data
pixelization scheme, which allows to handle large amounts of data as in the
SDSS photometric survey. Using spectroscopic and photometric data in the
redshift range 0.01<z<0.40 we obtain 5901 triplet candidates. We have used a
mock catalogue to analyse the completeness and contamination of our methods.
The results show a high level of completeness (~80%) and low contamination
(~5%). By using photometric and spectroscopic data we have also addressed the
effects of fiber collisions in the spectroscopic sample. We have defined an
isolation criterion considering the distance of the triplet brightest galaxy to
closest neighbour cluster, to describe a global environment, as well as the
galaxies within a fixed aperture, around the triplet brightest galaxy, to
measure the local environment. The final catalogue comprises 1092 isolated
triplets of galaxies in the redshift range 0.01<z<0.40. Our results show that
photometric redshifts provide very useful information, allowing to complete the
sample of nearby systems whose detection is affected by fiber collisions, as
well as extending the detection of triplets to large distances, where
spectroscopic redshifts are not available.
