en General پژوهشي Research Article Background and Aim:In recent years, the importance of families&rsquo; active participation in care delivery has increased dramatically. Nurses&rsquo; attitude is a key factor in the implementation and the success of programs which actively involve families in critical care delivery. The purpose of this study was to analyze the effects of relatives&rsquo; participation in critical care delivery on nurses&rsquo; attitude to collaborative care.Methods:This pretest-posttest quasi-experimental study was conducted in 2013 on 44 critical care nurses of ShahidRahnemoun Hospital, Yazd, Iran, who were recruited through census method. The intervention was the involvement of patients&rsquo; relatives in providing basic care services to their own critical care patients for three consecutive months. A demographic questionnaire and the Families&rsquo; Importancein Nursing Care-Nurses&rsquo; Attitude scale were used for data collection.The items of this questionnaire are scored on a four-point Likert scale. Scores of 52 and less are considered as nurses&rsquo; negative attitude to families&rsquo; participation in care delivery. The face and content validity as well as the reliability of the questionnaire were confirmed by respectively ten experts and the test-retest method. Study data were analyzed by using the SPSS software (v. 16.0) and via conducting the paired-and the independent-samples t tests and the one-way analysis of variance. The level of confidence was set at greater than 0.95. Results:The mean of nurses&rsquo; pretest and posttest attitude scores were 64.11&plusmn;9.64 and 65.93&plusmn;7.08. The difference between these two scores was not statistically significant (P=0.18). The pretest-posttest mean difference of the FINC-NA score of nurses whose first-degree relatives had the history of hospitalization in ICU significantly differed from nurses who had not such history (P<0.03).Conclusion:Study findings revealed that in overall, nurses had a positive attitude to relatives&rsquo; participation in care delivery. Although the study intervention had no significant effect on nurses&rsquo; attitude, their positive attitude to such an intervention can betaken into account by healthcare managers for developing more family-centered care programs. Nurses,Critical Care,Cooperative Behavior,Attitude 39 46 http://mcj.bums.ac.ir/browse.php?a_code=A-10-1-522&slc_lang=en&sid=1 Aliakbar Vaezi 10031947532846003686 10031947532846003686 No Assistant Professor, Department of Nursing, Faculty of Nursing and Midwifery, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran Zahra Alimandegari 10031947532846003687 10031947532846003687 No Zahra Alimandegari, Critical Care Nursing Graduate Student, Department of Nursing, Faculty of Nursing and Midwifery, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran Tel: +989137741929 E-mail: mandegar.zahra@yahoo.com Farahnaz Farnia 10031947532846003688 10031947532846003688 Yes Assistant Professor, Department of Nursing, Faculty of Nursing and Midwifery, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran Mohammad Hasan Lotfi 10031947532846003689 10031947532846003689 No Associate Professor, Department of Statistics and Epidemiology, Faculty of Public Health, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran