Construction projects are getting bigger and more complex. The services of multi- disciplinary teams of professionals are needed. To complete the projects on time, within budget and of required standards, concerted efforts of all team members are paramount. In Hong Kong, the HKSAR government has been promoting the use of the New Engineering Contract (NEC) for use in public projects on the belief that NEC can foster cooperation among the team members. Furthermore, incentives have been used to galvanize team effort in order to meet the project goals. This study posits to study the use of incentives under the NEC, in particular, how the Key Performance Index (KPI) can be used to monitor the attainment of the goals set under the incentive arrangement. Accordingly, Option X20 of the NEC was selected as the focus of this study. A questionnaire survey was used to collect views of practitioners as to what kinds of KPIs are suitable the operation of Option X20. The results of the survey indicated that cost- and time-related; objective and quantitative KPIs should be used as these are indicative of the achievement of collaboration. It is concluded that when suitable KPIs are selected with realistic and attainable targets, incentivizing effects can be materialized.