Background: The use of cell phones can harm nursing students' academic performance. As such, reliance on the device for everyday activities has increased. Consequently, "nomophobia", defined as the fear of being without one's smartphone, has emerged as a new phobia among the users. Aim: This study was aimed at identifying the effects that long-term use of smartphone has among students cause on their level of attention and learning styles. Methodology: A quasi-experimental study was carried out among nursing students in two public universities located in western Kenya. The sample size comprised of 811 third- and fourth-years nursing students with a control group (n = 349, 43. %) and an experimental group (n = 462, 57%). The experimental group left their cell phones, in sound or vibration mode, as they normally kept them, on a table located in the corner of the classroom. Data were analysed using SPSS v.25, and data presented using graphs and tables. The data was reliable at alpha .824 and without outliers. Results: More female 54.87% than male was evidenced by the responses. Both groups showed higher-than-average levels of nomophobia at the beginning of the class. As for problematic smartphone use and attention, it was found that there were statistically significant differences in both cases (U = 1355.500, Z = −2.830, P = .005; U = 1449.000, Z = −2.363, P = .018, respectively), and the experimental group had higher average scores, as well as in those related to knowledge. Testing of the hypothesis was done and the null hypothesis was rejected (X2=19.609, P>0.001). Conclusion: A relationship has been found between nomophobia and problematic smartphone use. Students who do not have access to their cell phones during class perceive more problematic cell phone usage, in addition to paying closer attention during class. Recommendation: Because of this, it is important to an alternative way of reducing the nomophobia in order to enhance attention and learning styles among students. Future studies are recommended on lecturers not only the students the medical students but also in other departments of the university and expand to other universities across the country.