Purpose To investigate the course of fatigue, subjective and objective language functions in patients with lower-grade gliomas during the first year of disease. Further, to examine if subjective and objective language variables predicted ratings of fatigue. Methods Fatigue was assessed with the Fatigue Severity Scale, subjective language with self-reported word-finding, expression of thoughts, reading and writing from the Functional Assessment of Cancer Therapy – Brain, and objective language with standardized tests. Mixed models were used to investigate changes in variables over time and predictors of fatigue. Results Twenty-three patients with gliomas (WHO 1–3) were included. Average ratings of fatigue did not change significantly, but altering patterns were observed. Subjective concerns about word-finding and expression of thoughts increased significantly during follow-up. The regression analyses showed that concerns about abilities to read and write significantly predicted fatigue. The results indicated that less concerns about reading and writing were associated with lower levels of fatigue. Conclusions Patients with lower-grade gliomas report fatigue and language concerns throughout the first year. Concerns about reading and writing call for careful consideration as they seem to provoke fatigue. The findings underline the importance of the patients’ perspective in treatment and follow-up.