The new photometric observations of PG 2303+243 were obtained in 2012 during a campaign carried out with three telescopes. The analysis of these observations is presented in this paper. We identified l = 1 and l = 2 pulsation modes. The pulsation periods were compared with theoretical ones for models of ZZ Ceti stars. This allowed us to estimate the physical parameters of PG 2303+243. The star seems to be cooler and has thicker hydrogen layer than it was thought before. We have derived M*/M⊙ = 0.66, Teff = 11014 K and log(MH/M*)=−4.246 for this star.