We hypothesized that adults with uncomplicated malaria have lower left ventricular contractile function compared to the general population and that this improves after antimalarial treatment. We examined uncomplicated malaria and the general population from the Western part of the Brazilian Amazon Basin. All persons underwent an echocardiographic examination and peripheral blood smears. Left ventricular function was assessed by speckle tracking analysis of global longitudinal strain (GLS). Logistic regression models were used to assess the association between malaria status (yes/no) and GLS and improvement in GLS by follow-up was assessed using a paired T-test. We enrolled 99 adults with uncomplicated malaria (mean age 40 years, 46% female) of whom 75 had Plasmodium vivax, 22 Plasmodium falciparum and two had both species [median 1595 (528 to 6585) parasites/mm(3)]. Seventy adults completed a follow-up examination after standard malaria treatment (median 31 days). We examined 486 from the general population (mean age 41 years, 63% female). In persons with malaria at baseline, GLS was lower compared to the general population (18.7% vs. 19.4%, P = 0.002) and GLS improved at follow-up (19.2%, P = 0.032). In multivariable models adjusted for clinical, socioeconomic and echocardiographic confounders, baseline GLS remained significantly associated with malaria status [odds ratio 2.45 (95%CI 1.00 to 7.25), P = 0.023 per 1% increase]. Parasite density was associated with worsening in GLS [+ 16% (+ 0% to + 34%), P = 0.047 per 1 unit increase in GLS]. Adults with uncomplicated malaria had lower GLS compared to the general population and this improved after completed antimalarial treatment. Our results suggest that malaria infection may affect left ventricular contractile function, however, further studies are needed to fully elucidate such a relationship.