BackgroundPatient reporting of their care experience is crucial for evaluating healthcare quality. Negative patient reports are often associated with missed nursing care, with previous research primarily attributing this to objective workload, neglecting the role of subjective workload. Furthermore, there is a gap in understanding the combined impact of patient and nurse assessments of missed nursing care on the overall patient experience. ObjectiveThis study aims to explore how the interaction of objective and subjective workload influences nurse-reported missed nursing care. Additionally, it investigates how the interaction of missed nursing care, as assessed by both patients and nurses, influences the patient's overall experience. DesignA quantitative daily diary design, employing a nested (shifts within nurses) and multi-sourced (nurses, patients, and objective data) approach, was implemented. SettingThe study was conducted in two medium-sized public hospitals, encompassing internal medicine and surgical wards. ParticipantsA total of 141 registered nurses providing direct patient care and 627 patients treated by these nurses participated in the study. MethodsParticipating nurses completed questionnaires during five morning shifts, detailing their experiences with specific patients. Concurrently, the same patients provided feedback through questionnaires. A dual moderated mediation model was analyzed using mixed-model regression analyses, suitable for the nested design. ResultsThe study supported the dual moderated mediation model. Subjective workload emerged as a statistically significant moderator, influencing the impact of objective workload on nurse-reported missed nursing care (β = −0.476, p = .009). Particularly, under high subjective workload, missed nursing care was higher during low compared to high objective workload. Moreover, patient-reported missed nursing care moderated the relationship between nurse-reported missed nursing care and patient experience (β = −0.411, p < .001). In instances of high patient-reported missed nursing care, positive patient experiences were observed with low compared to high nurse-reported missed nursing care. ConclusionsThis research emphasizes the need to recognize and address subjective aspects of nursing workload. Effectively managing these perceptions is vital for upholding high care standards and enhancing patient experiences. The study advocates for targeted strategies to manage workload effectively and improve patient–nurse communication, especially in high-workload healthcare settings.Tweetable abstract: Exploring the link between nursing workload and patient experience: revealing the impact of patient and nurse assessments on missed nursing care. #HealthcareQuality #NursingResearch.