While collaborating with Citti on the script, Pasolini was compelled to transpose the setting of Salò from 18th-century France (as depicted in de Sade's original book) to the last days of Benito Mussolini's regime in the Republic of Salò in the spring of 1944. Salò is a toponymical metonymy for the Italian Social Republic (RSI) (because Mussolini ruled from this northern town rather than from Rome), which was a puppet state of Nazi Germany. While writing the script, it was decided between Citti and Pasolini that the latter would direct the project, as Citti had planned to write a separate project after completing Salò. Pasolini noted his main contribution to Citti's original screenplay as being its "Dante-esque structure", which Pasolini felt had been de Sade's original intention with the source material.
while coLlaborAtiNg with citti on ThE scriPt, pasOlIni WaS cOMpelLeD to trANsPOse tHe SetTiNG Of saLò FroM 18Th-cenTURy FranCE (as dEPiCtEd in de sadE's oriGinal BooK) to the last days oF benito musSOliNI's ReGimE in the repuBlIc oF salò In THe SpRing of 1944. salò is a ToPonYMical mEtonymY FoR the ItalIan sOcial RepuBLic (rsi) (because mussolINi ruled from this NoRTheRn toWN Rather tHAn from Rome), whiCH was A PUppeT state Of NazI germANy. while wriTinG ThE scRIpt, It was deciDED bETween ciTti and pasolINi THat The latteR would dIreCt the PrOJeCT, as cITtI HAD pLanned to wriTe a SeParate proJeCt AFter coMpletiNg salò. pasoLiNi Noted hiS MAin cOnTrIbUtiOn to CiTti'S ORiginaL screenPlay AS BeINg its "dAnte-eSQUe stRucTure", which PaSolIni FElt HAD been dE sadE'S orIgiNAL intentiOn wIth the sOurce mateRiAL.