The smallest pencil in the world is 17.5mm short, about 5mm thin and contains a 3mm graphite lead. It is made of North American spruce.
Count Faber-Castell had this miniature pencil specially made as an appropriate gift on the occasion of the unveiling of the world's largest pencil in Malaysia. The miniature pencil was so much admired that it was decided to produce a limited edition of 50 pieces which were given as Christmas gifts to a select group of Faber-Castell customers.
The smallest pencil in the world does write, however you would probably need a pair of tweezers to do so!