Nakajima, 58, replaces Kaoru Tosaka, 65, who was the first president of the company after it separated as a subsidiary from parent conglomerate NEC in November 2002.
The change, which takes effect November 1, was approved by NEC's board of directors during their meeting this week.
Nakajima, a 35-year NEC veteran who presently serves as executive vice president and a boardmember, concurrently spearheaded NEC Electronics America as president and CEO last year. In March, Nakajima returned to NEC Electronics in Japan to serve as a corporate officer overseeing the company's large-scale-integration business development.
Nakajima takes on a company whose sales are dropping due to weaker than expected mobile-phone sales and lessened emphasis on its semiconductor business.
NEC earnings in its most recent quarter sank 1.2 percent to $10.6 billion from $10.8 billion in the same period a year ago.
Overall, NEC's profit for the first half of the year dropped 35 percent to $142 million from $218 million, while sales fell 3 percent to $19 billion from $19.9 billion in the same period a year ago.
Much of NEC's profit came from the sale of its associated companies and costs saved from consolidating resources, such as the re-launch of its Beijing NEC IC Design Company as NEC Electronics China, the company said.