It is common to use questionnaires and interviews to assess the emotions of staff who serve clients with intellectual disabilities. Remarkably, observations of actual staff behaviour and assessments of nonverbal expressions are usually not involved. In the present study, we have made a first start in the development of an observation instrument that registers both verbal and nonverbal expressions of emotion. Following extensive literature reviews, interviews with clinical experts and pilot observations, we have created an observation system and observed a team of staff members during a period of three months. Results revealed sufficient to good interrater reliabilities regarding the observation of the three forms of emotional expression: body movement, facial expression, and verbal utterances. Low levels of explained variances between the different forms of expression showed that predictive values were weak. This means that there is a surplus value of the observation of nonverbal emotional expressions as compared to existing instruments that base their assessment on verbal and/or written responses only. (Contains 2 figures and 1 table.)