Population dynamics of Gynaikothrips ficorum (Marchal, 1908) (Thysanoptera, Phlaeothripidae) and monthly fluctuations of thrips populations infesting Ficus benjamina trees were monitored in El- Zohria Garden, Cairo Governorate and in Smart village, 6 October city, Giza Governorate, Egypt. The relation between the population activity of the tested insect and weather factors were studied during the 2018 year months (January to December) on the ornamental trees Ficus benjamina. The obtained results indicated that the total stages of the Thrips G. ficorumhave two activity generations along the year of study . The number of eggs were significantly increased in July with 64 eggs and were slightly in October with 19 eggs. Presence of eggs was rare in August and September. The nymph stages were present from March and April with 39, and were slightly in December. Presence of nymphs was rare in August. Adults were active in May and June, reaching 39 individuals. The highest numbers of total thrips adults were observed in March and April. The number of adults were gradually increased reaching a maximum of 117 individuals.Statistical analysis of the data shows that the simple correlation and simple regression between the maximum, minimum temperature and relative humidity with the monthly mean of the total population, adults, nymphs and egg stages, of G. ficorum ranged between significant and highly significant at El- Zohria Garden, Cairo Governorate. The same trend was observed in Smart village, 6 October city. Generally the infestation of G. ficorum thrips in El- Zohria Garden, was more than that in Smart village.