Sociology relies heavily on the idea that social interactions with people in the network are important in changing minds and behaviours. Information on the personal networks of individuals is therefore of great interest to many researchers. Unfortunately, such data are rarely collected because of the respondent burden of naming many individuals in their network and repeatedly answering questions about these individuals. Using GENSI—a recently developed (freely available) graphical tool to collect personal networks—we collected large personal network data from a representative sample of Dutch women between 18 and 40 (N = 758) through the LISS-panel; a longitudinal internet survey of Dutch individuals. Respondents had to list exactly 25 names of individuals with whom they had communicated within the last year, and answered several questions about these individuals, including demographic characteristics and fertility outcomes. In this talk, we show the workings of GENSI; report on the experiences respondents had with the survey; and reflect on the quality of the responses. Our results show that collecting large personal networks is feasible through this method without burdening the respondents too much, generating unique data. The value of data on large personal networks in representative samples will be discussed for sociological questions.