Abstract: The present invention is directed to a multi-head multi-needle sewing machine system adapted to change threads by horizontally moving sewing heads, which system provides for space savings and further increase in the number of sewing heads and colors of threads to be employed. For this purpose, needle-bar support frames 6 are each guided in the horizontal movement thereof by one guide rail 31 horizontally extending over the whole length of a sewing machine system 1. A thread take-up positioning piece 63 for maintaining undriven needle thread take-ups 5 at a raised position is secured to place as extending substantially between the centers of adjacent arms 3. In this multi-head multi-needle sewing machine system 1, the movement ranges of the needle-bar support frames 6 of the respective sewing heads partially overlap with each other but there is no fear of interference therebetween because the needle-bar support frames 6 horizontally travel for the same amount in the same direction.