According to the so-called telescoping effect, there is a gender-specific course of alcohol dependence with women starting alcohol use later than men and having a faster development of harmful consequences. There are inconsistent data regarding a telescoping effect in opiate dependence. In each of six European centres, 100 opiate addicts were investigated by a structured interview (mainly the EuropASI and CIDI) at admission to various kinds of treatment (TREAT project). In a secondary analysis of the TREAT data, women and men were compared regarding age at onset of heroin use and the current severity of addiction. In addition, a comparison of female (n = 140) and male (n = 140) addicts matched for age and study centre were carried out. Eventually, multiple logistic and linear regressions were done with the interaction term of gender and time of regular consumption as predictor for the severity of dependence, besides, other sociodemographic variables. There was no difference between genders regarding the age at onset of regular heroin consumption. Up to 4 years of regular consumption, there are gender-specific differences in the course of opiate dependence, e.g. a faster progression of legal problems in men and social problems in women. There were no differences in the severity of dependence other than more economic problems for women. A telescoping effect could only partially be observed in this large sample of opiate addicts. A gender-specific course was limited to the first years of consumption, and included domains with a faster progression for men. It has to be assumed that opiate dependence is a rapidly developing disorder with early chronification. Afterwards, only individual courses with influences of the national treatment system were observed.