Patients' needs in asthma remain insufficiently understood and met. We therefore aimed to investigate the potential determinants of patients' needs in asthma treatment. Our study was based on survey data on 189 adults with asthma. Needs were measured using the 13-item Needs in Asthma Treatment questionnaire, which yields a total score and subscale-specific scores ('exacerbations', 'patient expertise', 'handling drugs' and 'drug effects'). We considered age, sex, education, years since diagnosis and anxiety/depression (measured by the Patient Health Questionnaire-4) as potential determinants. Associations were estimated by multivariable linear regression. Overall, we observed that younger age, poor mental health and a more recently established asthma diagnosis were independently associated with increased needs. Information on drug effects was an exception to this pattern as the need in that domain was solely determined by sex (being greater in men). In conclusion, our study provides novel evidence on patient characteristics that are associated with needs in asthma treatment. If confirmed by future studies, our observations may assist healthcare professionals to identify asthma patients with potentially elevated information, support and training needs and could contribute to the development of tailored interventions.