Many people who suffer traumatic brain injury (TBI) have long-term residual symptoms. This study evaluates post-TBI symptoms and disabilities seven to eight years after mild TBI (mTBI), with specific aims to evaluate gender and age differences, and whether repeated TBI leads to the deterioration of symptoms and function. Telephone interviews with 595 patients were conducted using the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) to assess post-TBI symptoms, and the Glasgow Outcome Scale Extended (GOSE) was used to assess disability. Thirty-four percent reported post-concussion symptoms (40% of females and 29% of males). The symptom burden was higher in women than in men, and higher in patients with repeated TBI. The distribution of symptoms was similar for women and men. Women reported a significantly higher level of disability on GOSE; 31% had not returned fully to daily life, compared with 17% of men (p < 0.001), the biggest difference being in the age group of 25–49 years. Patients with repeated mTBI reported significantly lower scores on GOSE; 31% had not returned fully to daily life, compared with 21% of the single-TBI patients (p < 0.05). After mild TBI, one of three patients reported at least one post-TBI symptom. Women and individuals with repeated TBI presented a worse GOSE outcome. These findings have implications for clinical practice and research and should be taken into consideration when planning the rehabilitation and follow-up of mTBI patients. This also emphasises the importance of informing patients about post-concussion symptoms and when to seek healthcare.