AIM: This study aims to explore the prevalence of smartphone addiction among nursing students and its correlation with their levels of insomnia, loneliness, and self-esteem. METHODS: In this correlational study, 515 consenting undergraduate nursing students studying in various nursing colleges,were enrolled through total enumerative sampling from April to November 2024. We excluded nursing students with a diagnosis or history of mental health problems (anxiety, depression, etc.). RESULTS: In the present study, 23.1% (N = 515) of the nursing students were found to have smartphone addiction. Most participants (66.03%) did not have clinically significant insomnia, followed by 26.21%, 6.79%, and 0.97% of participants with mild, moderate, and severe insomnia, respectively. The mean ± standard deviation of loneliness was 45.58 ± 8.98, with high levels of loneliness being most prevalent (64.46%). The mean ± standard deviation of self-esteem was 27.94 ± 4.89, and 66.21% of the participants had high self-esteem. The correlation analysis showed that smartphone addiction, insomnia, and loneliness, scores were significantly positively correlated (p < .01). On the other hand, self-esteem scores were negatively correlated with smartphone addiction, insomnia, and loneliness scores (p < .01). Multiple linear regression has shown that high levels of insomnia and loneliness and low self-esteem positively predicted smartphone addiction (p < .01). CONCLUSION: In summary, nursing students suffered high loneliness and were strongly associated with smartphone addiction, insomnia and self-esteem. Overuse on smartphone addiction can cause low self-esteem and increased insomnia can develop into sleep problems. Smartphone addiction among college students must be strictly monitored, and such individuals require reverent supervision and intervention programmes, so that it can be detected at an earliest. After academic hours, other sports, entertainment, and cultural programs should be considered to reduce the screen time.