For most international agreements to be ratified, the European Parliament (EP) should give its consent through a vote in its plenary. While EP consent is very rarely denied, the level of contestation of these votes does vary. A contested vote, i.e. with a relatively lower share of votes in favour of ratification, indicates a more critical position of MEPs vis-à-vis the agreement, and hence vis-à-vis the Commission’s proposal to ratify it. Beyond its decision on consent, the EP regularly gets involved earlier in the procedure in several ways, such as resolutions. This EP involvement allows both policy and office-seeking strategies. However, the consequences on inter-institutional relations, in particular on the degree of contestation, are not known. Therefore, this paper asks: does EP involvement before its votes on ratification of international agreements reduce the contestation of these votes? The paper considers the 340 agreements concluded by the EU since 2009 and four types of EP involvement: resolutions, expertise reports, parliamentary questions and plenary debates. Utilizing a regression, it analyses the patterns of EP activities in terms of frequency, nature and timing, and their relation with the contestation of votes. The analysis also takes into account the type of agreement, its policy field and its salience. Thus, the paper contributes to a better understanding of the consequences of early-stage parliamentary involvement on inter-institutional relations. This relation is explored as not only domestic politics are at stake, but also the relation of the EU with the rest of the world.