Congenital bilateral absence of the vas deferens (CBAVD) is a form of male infertility in which mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene have been identified. Here we identify different mutations of CFTR and the poly-T variant of intron 8 (IVS8) in Argentine patients and analyze sweat test values and clinical characteristic related to Cystic Fibrosis (CF). For counseling purposes the two most frequent mutations in Argentine CF population: deltaF508 and G542X were screened in wives. In all cases, it was possible to reduce the risk of CF/CBAVD descendants in these couples because none of the mutation were found in the 36 samples. Eight patients (23%) showed abnormal chloride values (> 60 mmol/l). A second group of 6 patients (18%) had borderline values of sweat chloride (40-59 mmol/l). We defined another group with 6 patients (18%), with normal sweat chloride levels (30-39 mmo/l) and a fourth group of 14 (41%) patients with sweat chloride below 30 mmol/l. deltaF508, the most frequent CF mutation in the Argentine population, was found on 15 of the 72 chromosomes (21%), R117H mutation was detected on 2 of 62 chromosomes (3%). Only one R347P allele was found on 28 chromosomes analyzed (2%). On a sample of 27 patients, IVS8 analysis showed a frequency of 6/56 chromosomes (11%) of 5T allele. Even though these findings present an improvement in the detection of mutations related to clinical correlations in Argentine CBAVD population, the search for other common and uncommon mutations should be continued.