Abstract Introduction: Sexually transmitted infections (STIs) and inadequate contraceptive awareness continue to remain major public health challenges among young adults. Nursing students represent a critical group who will serve as future healthcare providers and reproductive health counselors. Assessing their knowledge, attitudes, and perceptions regarding contraception and STIs is therefore essential for identifying gaps and strengthening sexual and reproductive health (SRH) training. Aims and objectives · To assess the knowledge, attitudes, and perceptions of nursing students regarding contraceptive practices and sexually transmitted infections, and to identify factors influencing their awareness and preventive behaviours. · To evaluate the attitudes and perceptions of nursing students toward the use of contraceptives and sexually transmitted infections prevention practices. Materials & Methods: A cross-sectional, questionnaire-based study was conducted among B.Sc. Nursing students at a tertiary institution in Mangalore. A total of 165 students were approached using convenience sampling, of whom 160 completed the questionnaire and were included in the final analysis. Data were collected using a pretested, structured questionnaire covering sociodemographic characteristics, contraceptive and STI knowledge, attitudes, and perceptions. Descriptive statistics were used to summarize responses, while associations between year of study and knowledge level were analyzed using the Chi-square test with a significance level of p < 0.05. Results: Participants had a mean age of 20.4 years, with females comprising 82.5% of the sample. While 94.3% had heard of modern contraceptives, misconceptions persisted, particularly regarding emergency contraception and protection against STIs. Knowledge improved significantly from first to fourth year (χ² = 10.92, p = 0.018), with 68.6% of final-year students demonstrating good knowledge compared to 31.4% of first-year students. Positive attitudes were evident, with 74.3% supporting open contraceptive education, though cultural hesitancy remained a barrier for many students. Conclusion: Academic progression positively influences SRH knowledge and attitudes among nursing students. Early curriculum reinforcement, interactive teaching methods, and stigma-free learning environments are essential to enhance future nurses’ competence in contraceptive counseling and STI prevention.