The smartphone has gradually become inseparable part of lives for many young adults worldwide, and brought certain undesirable consequences as well. Procrastination identified as a prevalent issue amongst students reflects failure of self-control and linked with addictive behaviours, including smartphone addiction. Whereas, conscientiousness, characterized by self-discipline and goal-directed behaviour, has been identified as a protective factor against maladaptive behaviours such as procrastination. Given the importance of these factors in academic performance and overall development of young adults and lack of studies in the Indian context, the present study aimed to explore the relationship between conscientiousness, procrastination and smartphone addiction among Indian students. In this study 110 college students (43 males, 67 females), aged 18-26 years were engaged through purposive sampling. The Smartphone Addiction Scale (Kwon et al., 2013), Big Five Inventory-Conscientiousness items (John & Soto, 2017), and the Lay Procrastination Scale (Lay, 1986) were administered. A correlational research design was employed, and data were analyzed using correlation, regression, and mediation analyses. Results indicated that conscientiousness was negatively correlated with both procrastination (r = -0.53, p < 0.01) and smartphone addiction (r = -0.39, p < 0.01). Mediation analysis further revealed that procrastination partially mediated the relationship between conscientiousness and smartphone addiction, with an indirect effect of conscientiousness on smartphone addiction through procrastination (β = -0.85, 95% CI: -1.85, -0.10, p < 0.05). The findings suggested that individuals with lower levels of conscientiousness were relatively prone to procrastination and increasingly susceptible to smartphone addiction. Present survey study emphasized the need of fostering self-regulatory skills and employ strategies to reduce procrastination in order to reduce smartphone addiction in young adults. Future researches may examine smartphone addiction along with procrastination and conscientiousness in the light of empirical and qualitative data.