Abstract. Traditional stability of the Swedish legislative and executive authorities functioning, manifested in the almost complete absence of parliamentary and governmental crises, was questioned by results of the general elections in September 2014. The Alliance of four center-right parties who ruled Sweden from 2006 to 2014 suffered a defeat having lost 32 of 173 mandates. Simultaneously, the informal coalition of three center-left parties that opposed to the Alliance in 2006-2014 increased its representation in the Riksdag from 156 to 159 deputies only. Thus, none of the two inter-party blocks has the absolute parliamentary majority (175) needed for the formation of the own government. At the same time, Sweden Democrats who first entered the Riksdag in 2010 have significantly increased their faction (from 20 to 49 deputies) and thereby strengthened their king maker position (holding the balance of power) in the new parliament. Yet this party is isolated and excluded from the cross-party interaction in the Riksdag because of its Islamofobia and anti-immigrant attitudes. The new government of minority (the Social Democrats and the Green Party) was approved by the Riksdag due to the negative parliamentarism principle which means that the government shall be deemed approved if it does not receive the absolute majority of votes against it. However, many subsequent government bills submitted to the Riksdag are likely to be rejected by the opposition parties of the Alliance with assistance of the Sweden Democrats. To avoid such situation, the government parties have to bargain with smaller center-right parties on particular issues and thus to form a required ad hoc parliamentary majority. After the last elections, the political establishment parties became much more dependent in their interaction on the Sweden Democrats' unpredictable behavior than before. All of these factors greatly complicate the Riksdag's and the government's work as well as sharply increase risks of governmental and parliamentary crises even to the extent of the government's resignation and pre-term elections. It is unusual for Sweden where such elections last took place in 1958.