In the last one hundred years, tractors with much more power replaced animals all over the world, except in developing countries. Besides the advantage in power, the use of tractors increases agriculture productivity and time efficiency of field operations. Despite the unquestionable advantage of tractors for agriculture performance, in recent years the interest by animal traction is growing, even in developed countries. It is important to understand why. This interest usually is linked to small scale farming, but not only. Environmental concern is one of the most significant reasons, in different aspects: use of working animals as a renewable source of energy; forest management in protected areas to protect soil physical properties related to compaction affected by tillage treatments; field operations in environment protected areas, among others. In old vineyards, but producing a high value output, plant spacing turn animal traction without alternative. The maintenance of the gene pool in domestic animals; the creation of jobs in rural areas, such as farrier, harness maker and implement manufacturer, are also important issues. New challenges: new implements must be designed and new mechanical solutions achieved.