Background: Sexually transmitted diseases (STDs) are a global public health concern, with significant implications for individual and community health. Despite advances in prevention and treatment, awareness and knowledge about STDs remain inadequate, particularly in rural and semi-urban areas like District Kullu, Himachal Pradesh, India. This study investigates the awareness and knowledge of STDs among adults in District Kullu, focusing on gaps in understanding specific STDs, risk factors, prevention, and treatment. Methods: A descriptive, cross-sectional survey was conducted over five months from January to May 2024. A structured questionnaire, comprising socio-demographic questions and 20 items assessing STD knowledge, was administered online to 400 adults aged 18 and above. Data were analyzed using Microsoft Excel and Epi Info V7 software to determine frequencies, percentages, and overall knowledge scores. Results: The study revealed a general awareness of STDs among 79.8% of participants. However, knowledge about specific STDs like syphilis, gonorrhea, and HPV was less comprehensive. Awareness of risk factors was moderate, with 72.3% recognizing unprotected sex as a risk but fewer acknowledging other factors like sharing needles and substance abuse. Preventive knowledge showed that 70.8% knew about condom use, but only 65.5% understood the importance of regular testing, and 57.3% were aware of vaccinations. Knowledge about symptoms and treatment was relatively strong, but gaps persisted, especially regarding the management of viral STDs and complications of untreated infections. Overall, 26.3% of participants had very good knowledge, while 17.3% had poor knowledge. Conclusion: The study highlights that while there is a foundational awareness of STDs in District Kullu, significant gaps exist in detailed knowledge about specific STDs, risk factors, prevention, and treatment. Targeted public health interventions are needed to address these gaps and reduce stigma. Culturally sensitive educational programs and improved healthcare access are essential for enhancing community knowledge, promoting safe sexual practices, and ultimately improving sexual health and well-being in the region.