Clinical observations suggest that tinnitus may interfere with programming cochlear implants (CIs), the process of optimizing the transmission of acoustic information to support speech perception with a CI. Despite tinnitus being highly prevalent among CI users, its effects and impact on CI programming are obscure. This study characterized the nature, time-course and impact of tinnitus effects encountered by audiologists and patients during programming appointments. Semi-structured interviews with six CI audiologists were analyzed thematically to identify tinnitus effects on programming and related coping strategies. Cross-sectional surveys with 67 adult CI patients with tinnitus and 20 CI audiologists in the UK examined the prevalence and time-course of those effects. Programming parameters established at CI activation appointments of 10 patients with tinnitus were compared to those of 10 patients without tinnitus. On average, 80% of audiologists and 45% of patients reported that tinnitus makes measurements of threshold (T) levels more difficult because patients confuse their tinnitus with CI stimulation. Difficulties appeared most common at CI activation appointments, at which T levels were significantly higher in patients with tinnitus. On average, 26% of patients reported being afraid of ‘loud’ CI stimulation worsening tinnitus, affecting measurements of loudest comfortable (C) stimulation levels, and 34% of audiologists reported observing similar effects. Patients and audiologists reported that tinnitus makes programming appointments more difficult and tiresome for patients. The findings suggest that specific programming strategies may be needed during CI programming with tinnitus, but further research is required to assess the potential impact on outcomes including speech perception.