The production of lettuce plants is quite high in quantity from year to year, but in its cultivation activities there are often attacks by armyworms (Spodoptera litura). This larval attack causes damage to plant leaves up to 75%. The use of synthetic pesticides is the only option but has a negative impact on the environment and health such as decreasing the level of human immunity. To reduce this impact, there is a need for alternative control solutions that are more environmentally friendly to reduce the use of synthetic pesticides. Cigarette butts contain the same content as whole cigarettes, namely nicotine, phenol, and eugenol. So that cigarette butts have the potential as an insecticide to control pest attacks. Based on this, it is deemed necessary to conduct research to determine the effectiveness of cigarette butts as an insecticide. The aim of this study was to determine the effect of the concentration of insecticide on cigarette butts on mortality and speed of killing of Spodoptera litura larvae. The method used in this study was a Completely Randomized Design (CRD) with one factor, namely the concentration of cigarette butt insecticides with four treatments and repeated five times so that there were 20 experimental units. The treatments were P1 control, P2 at 10% concentration, P3 at 30% concentration, and P4 at 50% concentration. The results showed that the application of cigarette butt insecticides had a significant effect on the mortality rate and speed of killing of Spodoptera litura larvae. The P4 treatment gave the most effective results where within 24 hours after application it could kill >50% of the larvae tested and the rate of killing speed obtained was 1.7 per hour.