Objective: The rise in the proportion of sex activities in adults & deficit usage of the suitable contraceptive procedures has increased the unintended pregnancy among teenage girls, abortion & STI (Sexually Transmitted among the adults of our country, Pakistan. The research work carried out to investigate the sexual activities & usage of the contraceptive methods among adult unmarried university students. Methodology: This was a transverse eloquent research work. This research work carried out with the utilization of the anonymized, self-organized questionnaire with adults who were the students in various universities of Lahore, city of Pakistan. We selected 6 different universities randomly. The recruitment of the nine hundred and sixty students carried out with the utilization of the PPS (Probability Proportional to Size) method of sampling. We included total 850 students in this analysis, remaining students were available without complete data. We used the descriptive statistics for the description of the findings. Results: Out of total 850 students, 12.40% students were from universities having health faculty & remaining students were from other universities. Sixteen percent (n: 135) students stated that they had experienced sex. The average age at the time of their first exposure to sex was 17.90 years (17.60 years for female students & 18.10 years for male students). The usage of contraceptive was high (greater than 75.0%) & it was higher when students had sex with their irregular partners (greater than 90.0%). Among these students, about 50.0% were using contraception regularly and most frequent utilized method was the use of male condom. The most common reasons for no usage of contraception regularly were no knowledge about contraceptive procedures, accidental sex, involuntary sex, reluctance to utilize contraception by partner & fear from the side effects of the contraceptive methods. High amount of the universities students with good knowledge of contraceptive & STI & those students who were present with highly permissive behaviors towards males & female’s sex before marriage were using contraception very regularly. Approximately, 11.0% students or their sex partners who experiences sex in past, were available with the pregnancy’s experience and total ten out of 12 pregnancies were available as unintended and nine pregnancies ended with abortions. Conclusion: The results of this research study showed the requirement for the improvement about the knowledge of contraception & STI among adult unmarried students to promote the regular use of contraceptive and to prevent the unintended pregnancy, miscarriage & STI. Keywords: Contraceptive, STI, unmarried, improvement, prevention, methodology.