The paper reports about the construction and standardization of a Situational Test of Intolerance of Ambiguity (STIA) suited for the Indian social set-up. Interaction of two components of ambiguity (`novelty' and `complexity') and four manifestations of intolerance accepted by the researchers (cognitive, affective, avoidance and aggressive responses) provides eight dimensions of intolerance of ambiguity (IA). Every item of the test presents a common situation related to either of the eight dimensions. Item analysis has been done by determining discriminative power of the test items and its stability. The final form of 40 item STIA is a balanced test of IA containing 19 negative items to control acquiescence response bias. The test possesses high internal consistency and temporal stability indices. Besides, evidences have been presented in support of content, concurrent and construct validities of the test. Separate percentile norms of the STIA based on responses obtained from 920 college students have been worked out for the two sex groups.