This article aims to analyze the factors associated with suicidal ideation in the COVID-19 pandemic. A cross-sectional home-based survey, with three-stage cluster sampling, was conducted with 4,203 adults from ten municipalities in the Mato Grosso, Brazil. The data collection was carried households to assessment of sociodemographic characteristics, substance use and behavior in the pandemic. The Level 1 Symptom Cross Scale was used to identify suicidal ideation and aspects of mental health (somatic symptoms, sleep disturbances, dissociation, depression, anger, mania, anxiety, thoughts, substance use and memory). Chemiluminescence was used to detect IgG anti-SARS-CoV-2 antibodies. The prevalence of suicidal ideation was 19.2%, and the associated with increased consumption of alcohol (RP=1.16), smoking (RP=1.30), COVID-19 symptoms (RP=1.03), having one's life affected (RP=1.04), mental illness (RP=1.09) somatic symptoms (RP=1.15), sleep disturbance (RP=1.30), dissociation (RP=1.24), depression (RP=1.24), anger (RP=1.11), anxiety (RP=1.26), substance use (RP=1.19), drug prescription use (RP=1.18) and memory (RP=1.87). Highlights the high prevalence of suicidal ideation related to COVID-19 symptoms, changes in behavior post-pandemic and mental health factors.