Strengthening patient participation is considered a crucial element of primary health care (PHC) nurses’ practice when working with chronically ill patients. The COVID-19 pandemic had extraordinary effects on PHC nursing routines and how chronically ill patients’ could be involved in their own care. This study investigates the adaptation of Spanish PHC nurses’ approaches to supporting the participation of patients living with chronic illness during the COVID-19 pandemic. To reach this goal, we interviewed 13 PHC nurses who practiced in PHC centers in Spain. The interviews were analyzed using thematic coding. Three themes emerged from the descriptions of the nurses: (1) High COVID-19-related workload, decreasing health promotion, and chronic care, (2) Emphasis on patients’ and families’ self-responsibility, (3) Expanded digital and telephone communication with fewer in-person consultations. Nurses felt especially challenged to uphold the support for vulnerable groups, such as older people or patients without family support. Future research should focus on how the participation of the most vulnerable chronic patients can be supported in the context of the growing relevance of remote care.