The stress and pressure faced by nurses working in critical care units are a leading cause of physical and psychological problems. Nurses have to take care of all domestic duties along with their level of s at the hospital. Often, they do not have enough time to talk about their stresses with family and friends; this causes non-assertiveness in their behavior. Instead of raising their voices against heavy workloads nurses start to perceive things wrongly and depress themselves. Nonassertive behavior caused frustration, hostility, sadness, and hopelessness. It can be possible only when nurses learn to protect their own rights and respect others’ rights. It is very complex to handle stress which arises due to problems at home or at work, faulty relationships, and several other strained situations. Aim: The primary aim of the present study is to improve the assertiveness of nurses working in critical care units to promote emotional intelligence, resilience coping abilities power to get rid of stress. Methodology: Randomization controlled trial research design was followed in the present research study. The staff nurses working in critical care units at least for one year was considered as the target population of the study. The systematic random sampling technique was adopted to select 60 nurses working in critical care units of two private hospitals for experimental and control groups. Parker`s Job Stress Scale was used to collect first-hand information from nurses working in critical care units. Results: The paired t-test on mean of pre and post-interventional assessment of experimental group found (t= -6.357*, df=29, p<0.05) negatively significant difference, whereas in control group t-value (t=3.730,df=29, p<0.05) is found nonsignificant.   Conclusion: Conclusively, the study finding revealed that the assertive training program has significant effect on job stress among nurses working in critical care units.