Background: Malnutrition is associated to treatment toxicity, complications, reduced physical function, and lower survival in cancer patients. Malnutrition or associated risk was observed in the Prevalence of Malnutrition in Oncology (PreMiO) study among cancer patients visiting their first medical oncology appointment. Oncologists, not nutritionists, evaluated the nutrition status of the patients in this research, which was a first. Objective: The aim of the study was to evaluate the prevalence of malnutrition in patients at first medical oncology. Methods: PreMiO was a prospective, observational study conducted at Department of oncology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh. For inclusion, adult patients (>18 years) had a solid tumor diagnosis, were treatment-naive, and had a life expectancy >3 months. Malnutrition was identified by the Mini Nutritional Assessment (MNA), appetite status with a visual analog scale (VAS), and appetite loss with a modified version of Anorexia-Cachexia Subscale (AC/S-12) of the Functional Assessment of Anorexia- Cachexia Therapy (FAACT). Results: Of patients enrolled (N=50), 51% had nutritional impairment; 9% were overtly malnourished, and 43% were at risk for malnutrition. Severity of malnutrition was positively correlated with the stage of cancer. Over 40% of patients were experiencing anorexia, as reported in the VAS and FAACT questionnaire. During the prior six months, 64% of patients lost weight (1–10 kg). Conclusion: Even on their first visit to a medical oncology center, malnutrition, anorexia, and weight loss are prevalent in cancer patients.