According to Boliviabella.com:
"Halloween is not celebrated traditionally in Bolivia. However, Halloween and Todos Santos (All Souls Day) are related. Halloween is "All Souls Day Eve". However, American families and Bolivians whose children attend the American schools in La Paz Cochabamba and Santa Cruz, have always celebrated and there is general knowledge of what it is. With the arrival of hundreds of American families to Santa Cruz in 1997 during the oil boom, people began to pick up on the fun. I held huge Halloween parties at my house to introduce all my friends to the typical American Halloween frenzy and they loved it! It hasn’t quite caught on among the general population though, probably because people are so busy with their Day of the Dead celebrations. My Halloween page is in Spanish because I've uploaded an explanation of what Halloween is and how we celebrate it for Bolivians. "