Measurement instruments to assess user satisfaction with Clinical Information Systems (CIS) and with the implementation of CIS are needed as part of multi-faceted evaluation of CIS. Seven years of experience in developing measurement instruments to assess staff satisfaction with CIS preceded the development effort that created the Clinical Information System Evaluation Scale (CISIES). The scale was developed using precursors of the CISIES and it was guided by an expert panel. Following its construction the 37-item measurement instrument was piloted as part of the assessment of a Critical Care Clinical Information System implementation at a medical center in Florida, USA. Results indicated satisfaction with the implementation, although not strong, at the time of administration. The results of the CISIES administration were used by informaticians at the research site to plan and execute an intervention to improve satisfaction with the implementation. Re-administration of the CISIES at the site to evaluate the success of this intervention is planned. The CISIES was found to be a useful instrument, easy to administer, acceptable to respondents, easy to score and understandable by non-researcher at the study site. Early indications are that it will be useful in the formative and summative evaluation of CIS implementations.