The serial advantage, defined as the gain in naming rate in the serial over the discrete task of the same content, was examined between grades and types of content in English and Greek. 720 English- and Greek-speaking children from Grades 1, 3, and 5 were tested in rapid naming and reading tasks of different content, including digits, objects, dice, number words, and words. Each type of content was presented in two presentation formats: multiple stimulus displays (i.e., serial naming) and isolated stimulus displays (i.e., discrete naming). Serial tasks yielded faster naming rates--irrespective of task content--in both languages. However, content-specific characteristics influenced the trajectory of the serial advantage between grades. Improvement in the serial advantage between grades was found to be greatest for word reading, which started off similar to object naming in Grade 1, but ended up similar to digit or dice naming by Grade 5. In addition, growth in serial advantage was found to be associated with growth in discrete naming rate only in grade level analysis. For individuals, greater serial advantage was found to rely on processing skills specific to serial naming rather than on differences in the rate of naming isolated items. Our findings suggest that group level findings may not generalize to individuals, and although practice and familiarity with the content on the naming/reading task may impact the development of serial advantage, isolated item identification processes contribute little to individual differences in the gain in serial naming rates.