The objective of this work is to analyze ergonomic factors in charcoal production using masonry kilns called “rabo quente”, in order to improve health, safety, comfort and productivity of kiln operators. The specific objectives of this work are: 1) to evaluate work conditions for the kiln operator; 2) to evaluate personal, social, economic and professional characteristics of the operator; 3) to evaluate the climate (temperature) at the workplace; 4) to evaluate the operator’s aerobic capacity; 5) to estimate the working load for the operator from measuring heartbeating during the day; 6) to estimate time spent in the carbonization operations; 7) to do a biomechanical evaluation of carbonization tasks. The results of the analysis of geographic and dafoclimatic characteristics, work system and daily work routine showed that the work conditions are appropriate. It was observed that the kiln operator is a young, mestizo and married individual, with few children and few dependants, low education, average height of 171,40 cm and average weight of 68,40 kg. Twenty per cent of the interviewees declared themselves as illiterate, catholic and from countryside. The global thermometer and humid bulb index values found at the work place were within the limits stipulated by the regulating standard, with no thermal overload occurring. By the results found by using Astrand test, it was concluded that the kiln operator has a good aerobic capacity. The carbonization activity is considered moderately heavy, and the working load is classified as heavy and moderately heavy for load and unload operations, respectively, for what pauses are needed during the day. The barrelamento and shipping operations are classified as moderately heavy; the operation of sealing, as light. By estimating time spent in the carbonization activity, it can be observed that the unloading operation took 41% of the day; loading and cleaning operations took 60% of the work routine, and the sealing operation took 61,6% of the 6-hour daily routine. The results of the biomechanical analysis showed that the limit working load recommended in all operations would not be supported in all articulations for most individuals. In the loading operation, at the steps of lifting up and moving the log, a compression of the lumbar 5 and sacrum 1 spinal disk (L5-S1) is possible, causing an injury if the exposure is frequent.