This research note presents an innovative dataset of Swiss MPs' interest ties between 2000-2011. The longitudinal analysis shows that the average number of interest ties per MP has more than doubled: from 3.5 in 2000 to 7.6 in 2011. Since the mid-2000s, public interest groups have accounted for approximately one out of two ties between MPs and interest groups, showing the strongest increase during the period. However, when looking at the most present individual groups, important business groups dominate and appear well connected with the governmental parties of the political right. Finally, interest groups are also able to forge themselves a strategic presence within the parliamentary committees that are the most relevant for their policy issues. Next research steps include the assessment of the (un)biased access of interest groups to the parliamentary venue and their policy influence