To analyze brand management strategies among Internet Service Providers in Thailand, and to study the relationship among knowledge, attitude, and consumers' selection of Internet Service Providers in Thailand. This research has conducted in 2 parts 1. A qualitative research, an in-depth interview of marketing directors of 5 leading Internet Service Providers in Thailand. 2. A survey research of 402 Internet users in Bangkok Metropolitan area. Questionnaires were used to collect data, and percentage, mean, Pearson's Product Moment Correlation and Multiple Regression Analysis were calculated by SPSS package program to analyze the data. Results of the research are as follows: 1. Brand management strategies among Internet Service Providers in Thailand are focused on individual users market. Instant package selling at computer and software stores is used as a major distribution channel, along with the uses of advertising to build brand's knowledge among consumers. Pricing is a key strategy to gain consumer's interest. 2. Knowledge and attitude collaboratively and significantly explain consumer's selection of Internet Service Providers. Knowledge is correlated with consumers' selection in every brand. However, the correlation between knowledge and attitude and between attitude and consumers' selection of Internet providers were found only in some cases.