We describe a new species of rock gecko of the genus Cnemaspis from Java, Indonesia, representing the first record of the genus for this Island. The new species was collected from the southern slopes of Gunung Muria, a dormant volcano in Central Java. The new species is easily distinguished from all congeners by having a maximum SVL of 58.1 mm in males and 56.9 mm in females; a pair of sharp conical tubercle clusters on the occiput; a warty bridge on the nuchal loop, extending from the upper tympanum and curving to the nape; dorsal tubercles not linearly arranged; 18–20 paravertebral tubercles; postmentals separated by one scale; gular, pectoral and abdominal scales, ventral scales of fore- and hindlimbs, and subcaudal scales keeled; no tubercles on lower flank; precloacal and femoral pores absent; enlarged submetacarpal scales present on the first digit of the manus; 38–40 ventral scales; 31–35 lamellae under fourth toe; two postcloacal tubercles on each side; enlarged median subcaudal scales row present; caudal tubercles encircling tail; and a sexually dimorphic ventral color pattern, with males having a yellow belly and females white and the ventral surface of the tail in males yellow proximally changing to white at mid-length, whereas in females, alternating black and white rings completely encircle the tail, which is black distally.