The effect of neem, Azadirachta indica A. Juss, on some biological parameters of Mahanarva fimbriolata (Stil) (Hemiptera: Cercopidae) was studied in the laboratory by using NeemAzal-T/S, Nimkol-LS, and an aqueous neem seed extract. Initially, the LC,, was estimated for nymphs. Later, nymphs fed on sugarcane, Saccharum officinarum L., roots were sprayed with the respective LC,, for each product. The adults were maintained in cages on sugarcane plants sprayed at the base with the maximum rate recommended commercially for the crop (3 liter/ha). Moistened cotton discs surrounding the base of the plant were used as oviposition substrates. The LCso values estimated for NeemAzal, Nimkol, and aqueous extract were 0.014, 0.225, and 0.611%, respectively. There was a reduction in spittlebug longevity, regardless of sex, in relation to the control. Males exposed to the neem products, and aqueous extract showed longevity reductions of approximately 50%, whereas for females the reductions were 55-60%. The neem products and extract reduced fecundity by 75-85%. Morphological and physiological changes were observed in 9% of the eggs from individuals submitted to NeemAzal. Neem-based products, especially NeemAzal, have potential for the control of M. fimbriolata.