Abstract. This article considers the activity of the Spanish Cortes in law production and the control of the executive during the six parliaments of the democratic government. It mainly examines the output of the lower chamber due to the asymmetrical bicameralism and weak status of the Senate. In Spain, the legislative output has been dependent on different situations of party government. In general terms, the Cortes have been always very active in controlling the executive and its participation in law‐making was highly relevant when there was a minority government. Because parties are central actors in parliament and due to the strong party discipline in the Spanish case, the author mainly studied parliament output from the viewpoint of strategies of opposition parties. Sometimes parties behaved in parliament procedures in a competitive way, while in others they behave cooperatively. There was a great variety of patterns of strategic behaviour on account of the different situations of party government and the diverse opposition parties. Half of the parliaments had minority governments in which minority parties played a very important role by supporting the government in parliament; however, the main opposition party was never the same since there were two changes of government.