In this study, uses of labor were characterized using the ‘Work Balance’ method in a sample of 30 farms representing the diversity of farming dynamics within the Drâa valley oases (South East of Morocco). The efficiency of labor was analyzed through the elaboration of work time uses per products’ outputs (either crops or animal source food), as well as labor remuneration (i.e. Euros per day). The results showed that almost half of total uses of labor (48.8%) are devoted to livestock, while the remainders 51.2% are used for crops. The labor required to raise livestock was mainly provided by family members (72%), whereas that required for crops was mostly assumed (64.8%) by hired laborers. In all farms’ types (either smallholder units, average or large farms), date palms constitute the most vital crop for the oasis farming system, given their contribution to incomes generation, as well as they enable positive synergies of crop/livestock integration, while adapting to the harsh climate conditions. At the opposite, livestock ensures variable roles, as it is mostly crucial within smallholder farms given their limited investment means, whereas large farms rear animals for diversification purposes. By contrast, large farms devote increased interest and investments to cash crops such as watermelon and date palms market varieties, with almost entirely hired workforce, and without any consideration for their ecological impacts, particularly on groundwater depletion. Return on investments rate defined as the annual incomes divided by the invested capital is only 10.1% in smallholder farms, whereas it reaches a value of 23.7% in large farms; average farms showing an intermediate value of 15.4%. Altogether, the results confirm that there is still for improvement of work uses and efficiency in the oasis farming system, taking into account the diversity of situations, and considering the existing constraints such as scarce water (exacerbated by the ongoing effects of the global warming) and land, as well as limited investment means in a majority of farms.