Persian manuscripts are among the most beautiful artistic productions in the field of miniature painting. The term “Persian” applies mostly to the linguistic-textual aspect rather than to the palaeographic-codicological one, so that under this term we can include manuscripts of Turk-Ottoman, Moghul Indian and sometimes European geographic provenance, coming from what is now the area comprised among Turkey and Northern India across modern Iraq, Iran, Afghanistan and Pakistan. Knowledge on the colorants used by Persian artists, though, is not so deep as is the knowledge of pictorial materials used in Western manuscripts. It is only recently that diagnostic studies have been applied to Persian miniatures [1,2,3], apart from the pioneeristic work by Purinton and Watters [4]. In particular, very few diagnostic information is available for what concerns the use of organic colorants in the palette of Persian artists, so that our knowledge on this aspect relies mostly on bibliographic sources such as Qanun us-Suvar (Canons of Painting) by Sadiqi Bek, a royal painter in XVI century Safavid Iran, or Gulistan-i Hunan (Rose Garden of Art) written by Qadi Ahmad at early XVII century. According to some scholars, only inorganic pigments were employed in Persian painting [5]. It is obvious that artists considered inorganic pigments for their superior covering power and their better resistance to pollutants, but this hypothesis could be a result of lack of diagnostic information and it must therefore be checked in the light of technological improvements in the analytical instrumentation. In fact, evidence of use of dyes on Persian manuscripts has been provided by non-invasive analysis of some volumes kept in Northern Italy libraries. UV-visible diffuse reflectance spectrophotometry (FORS) and spectrofluorimetry were applied in situ on these volumes; results showed that dyes were used in two ways: a) to dye the paper support, a practice relatively common in Islamic manuscripts but rare in Western manuscripts; b) to impart delicate hues to particular details in miniatures. For what concerns paper dyeing, different colours could be obtained, frequently inside the same manuscript: dark blue (obtained with indigo), pale green (a mixture of indigo and a yellow dye), red (henna) and yellow. The practice of dyeing paper can be possibly explained with the desire of highlighting text over a proper background, such as gold text on a dark blue surface, but sometimes this is not the case. For what specifically concerns miniatures, it has been found a wide use of anthraquinone dyes; according to the spectral features of both FORS and fluorimetry spectra, these seem to be of animal origin, though using non-invasive techniques only it has not been possible to distinguish among Mexican cochineal, Armenian cochineal, Polish cochineal, kermes and lac dye; historical considerations make Armenian cochineal or lac dye, imported from India, the most suitable candidates. In yellow painted areas, the evidence of saffron was found, which is not surprising considering that Crocus sativus was cultivated in Iranian area since Sassanian times.