Introduction Oncology has rapidly evolved over the past decades in terms of treatments and outcomes. However, it has also introduced challenges, particularly for non-oncologist physicians who, at some stage of the disease, encounter oncology patients. The increasing complexity of terminology, lack of updated knowledge, or insufficient training, along with other interdisciplinary communication barriers, can lead to less-informed clinical decisions, resulting in suboptimal treatment management. Objective This study aims to investigate knowledge and communication limitations with oncology among internal medicine and intensive care physicians to identify educational and operational gaps. Methods This was a quantitative study using a questionnaire administered to internal medicine and intensive care specialists and residents (third to fifth year) from three centers. Data was analyzed using SPSS software. Results A total of 91 responses were obtained (69 (75.8%) from internal medicine and 22 (24.2%) from intensive care), of which 76.9% (n=70) were specialists. Approximately 92.3% (n=84) reported daily or weekly contact with oncology patients. Fifty-eight percent (n=53) rated their knowledge of oncology terminology as "adequate," and 93.4% (n=85) disagreed that "first-line palliative treatment" and "first-line metastatic treatment" have the same meaning. The majority (72.5%, n=66) considered the terminology used to be "unclear," particularly in relation to prognosis. In 72.5% (n=66) of cases, respondents reported that clinical decisions could have been altered if more objective terminology had been used. More than 90% (more than n=82) supported the need for standardized oncology terminology and clinical summaries with prognostic information. Around 93.4% (n=85) stated that continuous education in oncology should be more accessible. Conclusions The study revealed significant gaps in communication and knowledge of oncology among non-oncologist physicians, highlighting the need for standardized terminology and greater accessibility to continuous education. These measures could improve oncology care and potentially influence health policies.