A latent variable analysis was conducted to examine the nature of individual differences in lapses of attention and their relation to executive and fluid abilities. Participants performed a sustained attention task along with multiple measures of executive control and fluid abilities. Lapses of attention were indexed based on the slowest reaction times in terms of both quintiles and the [tau] parameter from the ex-Gaussian distribution. It was found that the slowest, but not the fastest, RTs in the sustained attention task were related to a broad based executive control factor and a fluid intelligence factor. The results further suggested that only the working memory capacity and response inhibition sub-executive control factors were related to the slowest RTs, with the fluency measures not being related to any of the RT variables. The results are consistent with the idea that fluctuations or lapses in sustained attention, as indexed by the slowest responses, are related to executive control and fluid abilities. (Contains 3 figures and 6 tables.)