The Multidimensional Scale of Perceived Social Support which contains three subscales––family, friends, and significant other support––was administered to 2105 high school students in Hong Kong. Confirmatory factor analyses were performed on two competing models, and the model that fit the data was a hierarchical model in which the three first-order factors were produced by a higher-order factor of overall support. Results showed that the higher-order factor was completely redundant with the first-order factor of significant other support which appeared to measure both friends and family support at the same time. The significant other subscale therefore poses serious conceptual and measurement problems. Further analysis based on the family and the friends subscales showed that girls reported more friends but less family support than boys, and older adolescents also reported less family support than younger ones. Older girls reported the highest level of friends support, and younger boys reported the highest level of family support.