Field latex is an important raw material in Thailand, produced by a large number of smallholders and handled by numerous local traders. This diversity of stakeholders involved along the production and marketing chain could result in the variability of the latex quality delivered to the factories. Latex processing industries need a raw material with consistently specified properties. Therefore, it is crucial to identify the factors that could affect latex properties. However, a complete description of the practices from the farmer to the factory is missing. Thus, a study was conducted to (1) characterise the upstream practices, (2) identify variable practices and (3) analyse farmers' and traders' perceptions of field latex quality that are believed to influence their practices. A survey was conducted with 398 field latex producers and 182 field latex traders distributed in eight provinces of Southern Thailand. The results showed that some agronomic practices in the mature plantations presented homogeneity (planting material, weed control, management of the inter-row of the plantations) while others (fertilisation, tapping panel treatment, harvesting practices) presented important diversity. Farmers' and traders' post-harvest practices presented limited sources of contamination. Nonetheless, for both stakeholders, an important possible source of variability was the quantity of latex preservative used. Finally, the analysis of the practices and the perception of the stakeholders clearly showed that field latex quality was determined both before and after harvesting. Research is still needed to analyse the impact of some agronomic practices on field latex quality. Latex traders also appeared as key stakeholders dealing with the quality.