Hole-transport is an important process in electronic devices such as organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs). However, the molecular structures required for hole-transporting materials in OFET and OLED applications are quite different. In this paper, we examined the effect of alkylation onto a disk-like shaped molecule both in OFET and OLED devices. While the alkylation suppressed the hole-transport mobility in OFETs, the performance of OLEDs with the same molecules was very much improved by alkylation, where the luminance even exceeded that of a common hole-transporting material. The effect of alkylation on these devices is discussed.