The article discusses neo-circumflex, neo-acute and pre-resonant vowel lengthenings in Juraj Križanić’s “Čakavian-Kajkavian” subdialect, as evidenced by his writings. All (non-)lengthening positions in Križanić’s subdialect are thoroughly analyzed and systematically compared with the same positions in Štokavian, Čakavian, Kajkavian and Slovenian. This confirms the Čakavian genetic base of Križanić’s subdialect (which, unlike Kajkavian, displays the results of Čakavian pre-resonant lengthening) with an additional, probably morphonological, but quite early, isogloss of neo-circumflex lengthening in some of the Kajkavian positions, as well as perhaps a phonetic isogloss of neo-acute lengthening in a greater number of positions (the latter, too, may in fact be morphonological, yet lacking phonetic counterexamples). As shown by the data from Križanić’s dialect area, his subdialect, in terms of the lengthenings discussed, coincides with what we can deduce about the older situation in Ribnik, Križanić’s birthplace (the subdialect spoken in Ribnik has subsequently undergone considerable phonetic stress retractions and some later Kajkavian influence).