diff --git a/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiChatAutoConfiguration.java b/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiChatAutoConfiguration.java
index 29715e21f3..629a3cf14f 100644
--- a/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiChatAutoConfiguration.java
+++ b/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiChatAutoConfiguration.java
@@ -61,6 +61,8 @@ public class OpenAiChatAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
+	@ConditionalOnProperty(prefix = "spring.ai.openai", name = { "api-key", "chat.api-key" },
+			matchIfMissing = false)
 	public OpenAiApi openAiApi(OpenAiConnectionProperties commonProperties, OpenAiChatProperties chatProperties,
 			ObjectProvider<RestClient.Builder> restClientBuilderProvider,
 			ObjectProvider<WebClient.Builder> webClientBuilderProvider,
diff --git a/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiModelConfigurationTests.java b/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiModelConfigurationTests.java
index 7aa172c290..3b84988a0d 100644
--- a/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiModelConfigurationTests.java
+++ b/auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiModelConfigurationTests.java
@@ -386,4 +386,24 @@ void openAiApiBean() {
 			});
 	}
 
+	@Test
+	void imageOnlyApiKeyDoesNotFailChatAutoConfiguration() {
+		// Regression test for https://github.com/spring-projects/spring-ai/issues/1818
+		// When only spring.ai.openai.image.api-key is set (no chat or common api-key),
+		// OpenAiChatAutoConfiguration must not throw an IllegalArgumentException.
+		// The OpenAiApi bean for chat should simply not be created.
+		new ApplicationContextRunner()
+			.withPropertyValues("spring.ai.openai.image.api-key=IMAGE_API_KEY",
+					"spring.ai.openai.base-url=TEST_BASE_URL")
+			.withConfiguration(AutoConfigurations.of(OpenAiChatAutoConfiguration.class,
+					OpenAiImageAutoConfiguration.class, RestClientAutoConfiguration.class,
+					SpringAiRetryAutoConfiguration.class, ToolCallingAutoConfiguration.class,
+					WebClientAutoConfiguration.class))
+			.run(context -> {
+				assertThat(context).hasNotFailed();
+				assertThat(context.getBeansOfType(OpenAiChatModel.class)).isEmpty();
+				assertThat(context.getBeansOfType(OpenAiImageModel.class)).isNotEmpty();
+			});
+	}
+
 }