Immunization plays a critical role in reducing childhood morbidity and mortality from vaccine-preventable diseases. Despite its benefits, adherence to immunization schedules remains a significant challenge in Kenya, with only 76% of children receiving full vaccinations as per the 2014 Kenya Demographic and Health Survey. This study explores the factors influencing adherence to immunization schedules among children attending the Maternal and Child Health (MCH) Clinic at Vihiga County Referral Hospital. A quantitative survey approach was employed, involving 120 participants selected through simple random sampling. Data were collected using semi-structured questionnaires. Key findings highlighted that adherence is influenced by parental knowledge, socioeconomic status, healthcare access, cultural beliefs, and healthcare worker attitudes. Parents with higher education levels and awareness showed better adherence. Conversely, financial challenges, distance to healthcare facilities, vaccine shortages, and cultural or religious beliefs were significant barriers. Positive interactions with healthcare workers were associated with improved compliance, while negative attitudes discouraged adherence. The study concludes that adherence to immunization schedules is shaped by a combination of socioeconomic, cultural, and systemic factors. Recommendations include increasing public awareness through community education campaigns, improving vaccine accessibility, training healthcare workers on patient-centered care, providing financial support to low-income families, and engaging community leaders to address cultural misconceptions. A multifaceted approach is essential to enhance adherence to immunization schedules and reduce the burden of childhood vaccine-preventable diseases.