Field portable geochemical techniques and site technologies offer now instant response and flexibility for most exploration tasks. By providing relevant data within minutes, they allow safer field decisions and focus on the most promising finds, while saving valuable resources in sampling grids or drilling. More efficient laboratory analysis programs are supported by sample screening and homogeneity checking on site. Field analyses are not always as accurate as laboratory ones, but most of the time, can be correlated with them, allowing reliable decisions. The level of confidence in field-made decisions needs to be compared between later and less numerous laboratory analyses, and less precise but more abundant and immediate field analyses. It may be demonstrated that in many cases, the fit–for-purpose of the latter allows a better confidence level. Quality compromises associated with field analyses can, be reduced by the application of better sample preparation and QA/QC procedures. Most of the further development of on-site chemical analysis is expected to be based on its integration with lab methods and on sound QA/QC practice, allowing a precise evaluation of its confidence level and uncertainties. Mineralogical analyses are less demanding but offer promising approaches in both surface and drilling exploration campaigns.