Sudden sensorineural hearing loss is a hearing loss of >30 dB in at least three consecutive frequencies that occurs in 3 days. The aim of this study was to investigate anxiety and depression caused by sudden, idiopathic, one-sided hearing loss. The levels of anxiety and depression in patients with this type of hearing loss were determined using the Beck Anxiety Scale (BAS) and the Beck Depression Inventory (BDI) at the time of the patient's first visit. In total, 56 patients (32 men and 24 women) with a mean age of 32.8 ± 9.9 years (range: 20 to 58 years) were selected as the patient group and 45 individuals without symptoms of anxiety and depression were selected as the control group. The mean pretreatment air-conduction threshold and bone-conduction threshold were 61.1 ± 26.1 and 49.4 ± 13.8, respectively. In the patient group, the pretreatment mean anxiety, depression, and hopelessness scores were 19.5 ± 10.7, 11.6 ± 8.4, and 6.2 ± 4.7, respectively. The control group's mean anxiety, depression, and hopelessness scores were 4.1 ± 3.0, 3.8 ± 2.1, and 1.8 ± 1.0, respectively. For all the tests, the difference between the patient group and the control group was statistically significant (p < 0.001 for all). Hearing levels were not correlated with scores on the BAS, BDI, and Beck Hopelessness Scale (p = 0.1, p = 0.6, and p = 0.4, respectively). In conclusion, the results of this study show that sudden hearing loss can cause anxiety and depression. Questioning patients with sudden hearing loss about symptoms associated with anxiety and depression might be useful, and a psychiatric consultation should be requested if necessary.