diff --git a/esphome/components/mdns/mdns_esp32.cpp b/esphome/components/mdns/mdns_esp32.cpp
index 7704c1d649..b03455ea2f 100644
--- a/esphome/components/mdns/mdns_esp32.cpp
+++ b/esphome/components/mdns/mdns_esp32.cpp
@@ -26,16 +26,24 @@ void MDNSComponent::setup() {
   mdns_instance_name_set(this->hostname_.c_str());
 
   for (const auto &service : this->services_) {
-    std::vector<mdns_txt_item_t> txt_records(service.txt_records.size());
-    for (size_t i = 0; i < service.txt_records.size(); i++) {
-      // mdns_service_add copies the strings internally, no need to strdup
-      txt_records[i].key = service.txt_records[i].key.c_str();
-      txt_records[i].value = const_cast<TemplatableValue<std::string> &>(service.txt_records[i].value).value().c_str();
+    std::vector<mdns_txt_item_t> txt_records;
+    for (const auto &record : service.txt_records) {
+      mdns_txt_item_t it{};
+      // key is a persistent string in services_, no need to strdup
+      it.key = record.key.c_str();
+      // value is a temporary from TemplatableValue, must strdup to keep it alive
+      it.value = strdup(const_cast<TemplatableValue<std::string> &>(record.value).value().c_str());
+      txt_records.push_back(it);
     }
     uint16_t port = const_cast<TemplatableValue<uint16_t> &>(service.port).value();
     err = mdns_service_add(nullptr, service.service_type.c_str(), service.proto.c_str(), port, txt_records.data(),
                            txt_records.size());
 
+    // free records
+    for (const auto &it : txt_records) {
+      free((void *) it.value);  // NOLINT(cppcoreguidelines-owning-memory,cppcoreguidelines-pro-type-cstyle-cast)
+    }
+
     if (err != ESP_OK) {
       ESP_LOGW(TAG, "Failed to register service %s: %s", service.service_type.c_str(), esp_err_to_name(err));
     }