Byrsonima crassifolia leaves were extracted via maceration (BrMa), percolation (BrPer), soxhlet (BrSox) and sonication (BrSon). Spectrophotometric estimation of chlorophylls and analysis of cumulative extraction allowed the characterization of the extraction process. Under these experimental conditions, the extraction efficiency for each method was greater than 99%. The best yield was recorded by Soxhlet (7.29±0.21%), the best extraction rate was by sonication (m: 0.032±0.004; r²: 0.96±0.02) and maceration showed less variations in the estimation of chlorophyll a and b. On the other hand, pharmacological evaluation in a rat ileum strips allowed identify that BrMa, BrPer, BrSox and BrSon reduce the spontaneous contractions (E_max: 38.54±2.03, 28.9±1.6, 31.87±1.79, and 29.09±1.27%; EC₅₀: 11.6±2.38; 13.22±2.83; 39.74±2.64 and >50 µg/mL, respectively) of ileum strips in a concentration-dependent manner, however, the effects were significantly lower than papaverine (E_max: 59.32±2.57%; EC₅₀: 7.11±1.0 µg/mL). These results indicated that according to extraction method there are variations in the metabolic content as well as in the pharmacological actions induced by B. crassifolia extracts. Finally, there are a low correlation between extraction temperature (r > 0.87) and spasmolytic activity.