In this letter we discuss a new cosmological model-independent test for the cosmic distance duality relation ( CDDR ) , \eta = D _ { L } ( L ) ( 1 + z ) ^ { -2 } / D _ { A } ( z ) = 1 , where D _ { A } ( z ) and D _ { L } ( z ) are the angular diameter and luminosity distances , respectively . Using the general expression for X-ray gas mass fraction ( f _ { gas } ) of galaxy clusters , f _ { gas } \propto D _ { L } { D _ { A } } ^ { 1 / 2 } , we show that f _ { gas } observations jointly with type Ia supernovae ( SNe Ia ) data furnish a validity test for the CDDR . To perform our analysis we use 38 f _ { gas } measurements recently studied by two groups considering different assumptions to describe the clusters ( La Roque et al . 2006 and Ettori et al . 2009 ) and two subsamples of SNe Ia distance luminosity extracted from the Union2 compilation . In our test we consider the \eta parameter as a function of the redshift parameterized by two different functional forms . It is found that the La Roque et al . ( 2006 ) sample is in perfect agreement with the duality relation ( \eta = 1 ) whereas the Ettori et al . ( 2009 ) sample presents a significant conflict .