The present research examined the effects of the need to belong and being informed or uninformed on the reactions of the participants to being ostracized. One hundred and twenty university students participated in the study. Ostracism was manipulated by "Cyberball", a virtual ball-tossing game, in which participants were initially included by three other players and then were excluded subsequently during the whole session. In the informed condition they were told that one of the players might be ostracized; in the uninformed condition they were not told anything about being ostracized. In the control condition, the participants were included to the game. When the game was over, the participants reported their positive and negative feelings, need satisfaction and impressions about the other players. Results revealed that participants who were ostracized, whether informed or uninformed, reported lower satisfaction of needs, lower positive and higher negative feelings and lower positive impressions about the other players in comparison to the included ones. There were no significant differences between the informed and uninformed targets of ostracism in the satisfaction of the fundamental needs, in positive and negative affect and in the impressions about the sources of ostracism. On the other hand, high or low need to belong had no differential impact on reactions to ostracism. Hence the results of the study supported Williams' model (2001; 2007; 2009) which suggested that the immediate reactions to ostracism were not influenced by neither situational nor individual difference variables. On the other hand there was a significant difference between informed and uninformed participants in the satisfaction of the self-esteem need. This result which seemed to be incongruent with the other findings was accounted by the sociometer theory.