Objective: Carmenta foraseminis (Busck) Eichlin is a plague of economic importance for the cultivation of cocoa and is widespread in all the San Martin Region, Peru. The study aims to determine the environmental factors such as temperature, relative humidity and altitude associated with pest incidence in cocoa fruits and associated with occurrence of fungal diseases in three districts of the San Martin region. Methodology: Eight plots, adjacent to meteorological stations, were selected and daily records of temperature and relative humidity were obtained. The altitudes were recorded with a GPS. Simultaneous to the incidence of C. foraseminis, the presence of Phytophthora palmivora "brown rot", Moniliophthora roreri "monilia" and Moniliophthora pernicious "witch's broom" were evaluated categotizing the fruits in three levels as follows: Level 1: fruits with presence of C. foraseminis; Level 2: fruits with presence of C. foraseminis + pathogen; and Level 3: fruits totally damaged with the presence of C. foraseminis + pathogen. A total of 1320 fruits were evaluated by checking inside for the presence of pest larvae and fungi based on their symptomatology. Results: The incidence was 36.4% in the evaluated areas. The district of Juanjui registered the highest incidence (54%), Tabalosos (30.2%) and San Roque de Cumbaza (25%). The highest levels of damage were observed at level 2 (41.7%) and level 3 (34.3%) and the lowest at level 1 (24%). Scope: The incidence of C. foraseminis had a positive relationship with temperature (P=0.033), but was not related to altitude or relative humidity. The damage of the insect positively influenced the development of the fungi P. palmivora "brown rot" (P=0.004) and M. roreri "monilia" (P=0.009), but it did not influence M. perniciosa "witch's broom" (P = 0.362).