Plant leaves are natural receptors of atmospheric pollutants and have recently been used in the field of environmental biomonitoring due to their usefulness for large-scale measurements and low cost. Despite growing research in this area, the is no standardized methodology for the characterization of organic and inorganic compounds on the leaf surface, which hinders researchers in selecting appropriate techniques. This study aims to address this gap by answering the question: “What are the methodologies for the characterization and analysis of organic and inorganic compounds in the phyllosphere or on the leaf surface?” For this purpose, a systematic review was conducted to compile and compare the methodologies applied to characterize, observe, or analyze the particular matterial on the leaf surface, thereby facilitating informed methodological decisions in future environmental studies. To achieve this, a literature review was conducted for the period between 2014 and 2024 using the ProKnow-C methodology (Knowledge Development Process—Constructivist) in order to identify and characterize the methods employed for the analysis of compounds on the leaf surface. A total of 135 articles were analyzed, identifying China as the country with the highest number of publications and 2024 as the year with the greatest scientific production on the topic, demonstrating a significant growth in research interest in this field. The methods identified were grouped into five main categories, with gravimetric techniques being the most frequently used. The review highlights the lack of standardized methods in the reviewed studies, which hinders reproducibility and comparability. Through the compilation, a methodological reference was created that provides a basis for options in future studies, depending on the type of compound being analyzed and the specific research context, contributing to future efforts toward method standardization.