Purpose This study aims to determine system quality (SQ) and information quality (IQ) characteristics of voice assistants (VA) on smartphones that are affecting users' satisfaction and technology acceptance, and how these affect behavioral intention (BI) to use. Design/methodology/approach This study uses the integrated model of user satisfaction and technology acceptance to evaluate users' behavioral intention to use VAs on smartphones. The model represents a causal chain from the key characteristics of SQ and IQ to beliefs and attitudes that ultimately affect use. An online survey was conducted with 75 university students, and the data was analyzed using multivariate analysis: Simple linear regression analysis and multiple regression analysis. Findings While SQ and IQ of VAs had stronger effects on perceived ease of use (PEU), information satisfaction and PEU showed significant influences on perceived usefulness (PU). The results supported the influence of PEU, PU, and attitude on BI to use but with lesser effect than what PU and attitude together had on BI. Research limitations/implications The sample was drawn from a population of students at a single and small university. Although this study received 160 responses, only 75 were appropriate for analysis. Originality/value There is no research, which adopts technology acceptance and user satisfaction approaches to VAs. To measure the causal effects, this study determined system and information characteristics that could explain SQ and IQ of the current VAs on smartphones. This study tested the proposed framework within the scope of the integrated approach.