This paper shows an assessment exercise of the air pollutant emissions measurement methods required by the IDEAM and environmental authorities, particularly the stack particulate matter isokinetic sampling and the diésel exhaust opacity measurement. The assessment methodology included the identification and assessment of critical factors, a review of currently applied controls and a practical performance assessment exercise. Serious training of the personnel in charge of isokinetic sampling resulted in misinterpretation of sampling methods, which means that a training and certification scheme is needed. On the other hand, the individual characteristics of the opacity meters and the appropriate design of the software to comply with the technical standards are not well known by suppliers. Therefore, better accreditation procedures for the technologies being imported are needed.