As far as we know, the Dong (VND) is the world’s least valuable currency unit, with a value of only SEK 0.0004. After that comes the Turkmen Manat, SEK 0.0005. The Iranian Rial, Laotian Kip and Indonesian Rupiah all have an approximate value of SEK 0.0008.
In Europe, the Hungarian Forint has the lowest value, about SEK 0.036. The Icelandic Crown has lost half its value since the financial crisis and has a value today of 0.058.