Purpose <p>Non-Hodgkins’s lymphoma (NHL) patients’ body mass index (BMI), information needs, and self-efficacy to manage illness vary over the course of treatment and are correlated to their physical and psychological health. The purpose of this study was to assess BMI, performance status, information needs, and self-efficacy to manage illness, and study their effects on symptom distress and anxiety in patients with NHL.</p> Methods <p>This prospective longitudinal study recruited NHL patients from a medical center in Northern Taiwan. A total of 47 NHL patients were followed before treatment (T0), at 6&#xa0;weeks after beginning treatment (T1), and at 15&#xa0;weeks after beginning treatment (T2). Generalized estimating equation analysis was used to examine the factors associated with symptom distress and anxiety.</p> Results <p>Self-efficacy to manage illness increased from T0 to T2 and was lowest at T0. Symptom distress slightly increased from T0 to T1 and then decreased at T2. Anxiety and information needs decreased from T0 to T2 and were highest at T0. Less symptom distress was associated with less anxiety, higher information needs, and higher self-efficacy to manage illness. Greater anxiety was associated with greater symptom distress, higher information needs, and less self-efficacy to manage illness.</p> Conclusion <p>Information needs and self-efficacy to manage illness were important factors influencing symptom distress and anxiety in patients with NHL. Healthcare professionals should provide patient-centered education as part of pre-treatment care to facilitate self-care, empower self-efficacy to manage illness, and improve symptom distress and anxiety.</p>