A prospective longitudinal study was performed to investigate the sensitivity to change over time of the Swedish Self-Evaluation of Communication Experiences after Laryngeal Cancer questionnaire (S-SECEL), addressing communication dysfunction in patients with laryngeal cancer. Twenty-six consecutive patients attending a weekly tumour conference over a period of one year at Sahlgrenska University Hospital were included in the study prior to start of treatment. The patients answered four questionnaire repeatedly in the course of one year: the S-SECEL, the European Organization for Research and Treatment of Cancer (EORTC), the Core Quality of Life Core Questionnaire (QLQ-C30) supplemented by the Head and Neck cancer questionnaire module (QLQ-H&N35), and the Hospital Anxiety and Depression (HAD) scale. In addition, performance status was assessed. The S-SECEL questionnaire was well accepted by the patients, and compliance was satisfactory with a cumulative response rate of 88% at one year, supporting its feasibility in clinical settings. Repeated measures with the S-SECEL over one year demonstrated a significant decrease in voice and speech dysfunction. The correlation pattern over time between the S-SECEL and the EORTC and HAD questionnaires lent support to the construct validity of the S-SECEL and indicated that the questionnaire was sensitive to clinical change. The changes in S-SECEL correlated most strongly with changes in the EORTC QLQ-H&N35 speech scale, moderately with changes in the QLQ-C30 role and emotional functioning and global QoL scales, while the weakest correlations were with changes in physical functioning. The S-SECEL was sensitive to changes in communication dysfunction, with convergent and discriminant validity of longitudinal assessments, and with relevance for the quality of life of patients with laryngeal cancer receiving different treatment modalities.