Back Ground : Technology is the practical application of knowledge, especially in a particular area (ICU). A Quasi-experimental design was used to evaluate the impact of applying guidelines on nurses' perception regarding negative aspect of using technological devices in critical care units. It was conducted in critical care units of Port-Said General Hospital, El- Zohoor Hospital, Port-Foad Hospital, El-Mabarrah Hospital (Health insurance) and El-Tadamon Hospital. The study samples consisted of 112 nurses working in the previous mentioned settings. The data was collected through a structured questionnaire to assess nurses` perception about negative aspects of using technological devices in critical care units. The results revealed that the nurses' perception regarding the negative aspects increased when compared between pre- intervention (5.4%), post-intervention (83.9%) and follow up (84.8%) with high statistically significant difference as (p=0.000). In multivariate analysis, the model explains 41% of the change in nurse's perception in related to negative aspects after intervention. It could conclude that, educational guidelines would be benefits. The study recommended different strategies for nursing practice to enhance nurses` perception regarding use of technological devices in critical care such as handout with Arabic language including comprehensive information about all aspects of technologies.