The major purpose of this study was to determine the pattern of dropout among secondary school students in Delta State. To guide this study, 7 research questions were asked and answered, 3 hypotheses stated and tested at 0.05 level of significance. The design of study was ex post facto using the past school attendance registers as the major instrument. The samples of the study consisted of 120 senior secondary schools and 120 vice principals. The collected data were expressed in percentages, and analyzed with t-test statistic. The major findings of this study included: (i) a higher percentage of dropouts in SSI, and a decline in SSII; (ii) a higher percentage of dropouts among females in all parameters; (iii) a higher percentage of dropouts in rural schools; (iv) a higher percentage of dropouts in mixed schools; (v) a higher percentage of dropouts in public schools; (vi) a significant difference on percentage dropouts between male and female single sex schools; (vii) a significant difference on percentage of dropouts between mixed and single sex schools; and (viii) a significant difference on percentage dropouts between schools in urban and rural areas. It was concluded that the single most important factor, which influenced pattern of dropouts, was student's sex.