This paper aims to provide insight to decision makers such as designers, facility managers and renovators of office buildings on how office occupants perceive acoustical comfort. In the first step, a detailed literature analysis was performed to determine the main criteria that can be used to measure acoustical comfort in office buildings. In the second step, interviews were undertaken with 12 facility managers, and work orders related to acoustical comfort were extracted from facility management and computerized maintenance management software systems. As a result, a list of occupant feedback and complaint types related to acoustical comfort were determined and a hierarchical structure was established. In the third step, a survey was conducted with 308 office employees to determine (1) the importance and satisfaction levels in acoustical comfort criteria and (2) number of respondents who have complaints in each complaint type. The findings present the common reasons behind acoustical discomfort and consequences of poor acoustical performance. It can be concluded that the occupants are more dissatisfied with the lack of acoustical privacy than with the level of noise or echo. In terms of noise level, occupants are most dissatisfied by ‘noise due to conversations’ compared to other sources of noise such as footsteps, ventilation or office equipment.