Population ecology ofPeriplaneta fuliginosa(Serville) was studied, using mark-recapture techniques, at a suburban residence in southeast Texas (Brazos Co.) from Mar. 1974–June 1975. Peak adult populations (3135♀: 2383♂) were attained during June 1974 while lowest levels were reached in Feb. 1975. Throughout the study period adult females were more abundant than males.Outdoor populations of nymphs and adults were active during every month of the study; however, more eggs and nymphs overwintered successfully than did adults. Seasonal activity patterns for all nymphal size classes and male and female adults were similar.Correlation coefficients (r) for activity of nymphal and adult stages vs. maximum daily temperature ranged from 0.54 for small nymphs to 0.70 for total catch. Correlation coefficients increased with cockroach size class from small to large nymphs to adults. There was a highly significant regression in each case of trap catch vs. maximum daily temperature.Of 3181 marked adults, 1664 were recaptured one or more times. Mean number of recaptures per recaptured female was greater than the mean for males. Days between 1st and last capture for females were 38.34±1.60 (range 2–363) days; for males, 38.01±1.61 (2–267) days. The difference was not significant.Of adults recaptured, 59% moved one or more times a distance greater than 3 m. Mean number of moves per recaptured females (1.342) and recaptured males (1.114) was significantly different (t = 2.86:P<0.004). A test of proportion of females moving and not moving vs. males moving and not moving revealed that a significantly greater proportion of females move (χ2= 4.46:P<0.05). Mean distance of 1189 movements made by females was 9.77±0.23 (3–109) m and of 868 male movements was 9.75±0.29 (3–25) m; mean distances moved by each sex were not significantly different. The necessity for females to locate suitable oviposition sites within the habitat is thought to explain the difference between male and female movement frequencies.