Cost estimators play an important role in an organization, as they produce most predictions of probable final construction cost. Since both under- and overestimates can be costly, attention should be paid to the estimating tasks. People involved are therefore likely to experience a considerable amount of mental and emotional stress as a result of inaccurate estimation. The types of stress can be divided into objective stress (OS), subjective stress (SS) and emotional exhaustion (EE). The research described in this paper examined the relationships between OS, SS, EE and stressors based on a survey of construction cost estimation personnel. T-tests, factor analyses, correlation analyses and regression analyses were applied to identify differences between the professional estimators and other personnel, and the types of stress endured. The results indicate that the stress levels of both the professional estimators and other personnel are similar, with OS being significantly higher than SS, which is in turn significantly higher than EE. For professional estimators, increased levels of OS were found to be mainly associated with lack of autonomy and unfair reward and treatment. Increased SS and EE, on the other hand, appeared to be a function of relationship conflict, work underload, lack of feedback, lack of autonomy and unfair reward and treatment.