This dissertation investigates the nature of second language induced first language attrition in the distribution and interpretation of overt and postverbal subjects in Serbian/Croatian/Bosnian (S/C/B). Data are collected from two groups of native speakers of S/C/B who have immigrated to the Netherlands, and compared to data from monolingual speakers of S/C/B. At the time of the data collection, the participants in the first group had been living in the Netherlands for more than 12 years, whereas the participants in the second group arrived in the five years prior to the study. Both groups work and live in a Dutch language environment. The results show that the group that has been in the Netherlands for a shorter period of time and has lower proficiency in Dutch differs most from the monolingual group. Furthermore, in the group that has been in the Netherlands for a longer period of time, the production of preverbal subjects appears to be affected by attrition (i.e. shows an increase), whereas interpretation of preverbal and postverbal, and overt and null subjects shows no effect. The findings are discussed within a range of linguistic theories.