<p>Herbal or traditional medicine (TM) is widely used among chronic disease patients. The Indonesian government actively supports the development and integration of herbal remedies, including phytopharmaceuticals, into the national healthcare system. The support is grounded on Law Number 17 of 2023, which delineates the role of natural medicines. The purpose of the study is to describe the use of TM and the factors associated with TM use among hypertensive and diabetic patients in Yogyakarta City, Indonesia. This study is a cross-sectional design. The respondents were patients with hypertension or diabetes mellitus, and comorbidities were excluded. They were selected conveniently when they attended the Primary Health Centre (PHC) in Yogyakarta, Indonesia. Data were gathered between July and August 2024 using a pretested questionnaire. The measured variables included TM use and the following variables: gender, age, education level, income level, TM knowledge, source of TM information, family support, neighborhood support, friends and other social support networks, and medication adherence. Data were analysed using descriptive, bivariate Chi-square, and multivariate logistic regression. Ninety-nine hypertensive and 100 diabetic patients resulted in 199 study participants. All participants used prescription medicines, and 51% (n = 199) reported using TM. The use of TM was 47% and 56% in hypertensive and diabetic patients, respectively. The most commonly used TMs were cucumber (36%) and garlic (18%) for hypertensive patients, while bitter melon (28%) and ginger (10%) were for diabetic patients. Several main reasons for TM use were feeling healthier (59%), hereditary from the family (13%), cheap (6%), easy to obtain (6%), easy to make by themselves (6%), minimal side effects (6%), and taste good (6%). As many as 68% and 61% hypertensive people had good adherence among TM and non-TM users, respectively. In diabetic individuals, 50% and 54% have good adherence for TM and non-TM users, respectively. The study indicated there was no significant association between various factors and the use of TM in hypertensive and diabetic patients. Gender, age, education level, income level, adherence to prescription medication, and support from family and friends were not significantly associated with the use of TM. For hypertensive patients, peer support and TM information sources show significant bivariate relationships with TM use, while for diabetic patients, personal knowledge and information sources are key factors. Multivariate analysis reveals no independent predictors for TM use in diabetes, but the TM information source emerges as the sole dominant predictor in hypertension (OR: 5.67, p = 0.018). The findings highlight the critical importance of information channels in facilitating the adoption of TM among hypertensive patients, with exposure significantly increasing the likelihood of usage. The absence of independent predictors in diabetes after adjustment indicates that various factors, such as knowledge and support, may interact in complex ways, thereby diminishing the impact of individual factors. Healthcare providers must prioritize verifying the quality of TM information through reliable channels to reduce risks.</p>