This study aim to determine the characteristics, roles, responsibilities, and challenges of informal caregivers for adult patients in Saudi Arabia. : Adult patients who have informal caregivers were invited to participate in a cross-sectional study. The inclusion criteria were patients who were 18 years old or older and permanent Saudi residents. A self-administered online questionnaire was used to identify patients' demographics, roles, responsibilities, and care challenges. Data collection lasted four months. Percentages, means, and standard deviations were reported in the analysis. The study included 276 participants, mostly female (68.8%), with a mean age of 55.21 years (SD = 20.3). Over half were married (56.2%) and not employed (81.9%). Common chronic diseases were diabetes and hypertension, with 55.8% using up to five medications. Caregivers were mainly sons or daughters (62%) living with the patient (84.1%). The top caregiver tasks were escorting patients to appointments (63.4%), scheduling doctor appointments (60.1%), and tracking medication refills (59.4%). Common challenges included caregivers lacking time (45.3%), inconsistent care (35.9%), financial constraints (27.5%), and caregivers missing doses (27.9%). The top not encountered challenges were inappropriate medication storage (78.3%), communication barriers (74.3%), improper disposal of injections (72.5%), medication management errors (71.4%), and lack of empathy (70.3%). This study highlights the vital role of informal caregivers in managing chronic illnesses in Saudi Arabia. Informal caregivers face challenges such as time constraints and financial limitations. The findings emphasize the need for better support systems, including training programs and improved access to healthcare resources, to enhance care quality for patients.