Background: Knowledge, attitude and behavior of dietary salt determine sodium intake. Among controlled (CHT) and uncontrolled patients with hypertension (UHT), however, limited information is available. The purpose of the study was to identify knowledge, attitude and behavior toward dietary salt and to define the nescience among hypertensive patients in Indonesia. Methods: Descriptive cross-sectional study design invited subjects using purposive sampling in a general hospital in Yogyakarta. The inclusion criteria were adult patients with hypertension and able to speak Bahasa Indonesia. The demographic data and knowledge, attitude and behavior toward dietary salt were assessed. Data were collected in cardiac clinics in Indonesia and analyzed using Mann Whitney and chi-squared tests. Results: A total of 175 participants joined the survey with dominantly males, mature age, married and having basic education level. The CHT group had higher knowledge, attitude and behaviour's percentage on healthy eating, problems-caused by high salty diet, reducing fat and salt consumption than the UHT group although it was not statistically proved. Both groups reported nescience about recommended amount of salt consumption (84.1% versus 81.1%, CHT and UHT respectively), salt-sodium difference (56.5% versus 59.4%), nutritional information (43.5% versus 48.1%) and food labelling (39.1% versus 40.6%). Limited participants always considered packaged indication (7.2% versus 11.3%) and total salt/sodium per package was more favourable label (42% versus 31.1%). Conclusions: Results showed no significant differences of knowledge, attitude and behavior between patients with controlled and uncontrolled hypertension. Both groups had problems on concerning recommended amount of salt consumption, nutritional information, and food labelling which should be addressed while teaching patients about hypertension.