diff --git a/src/excel_mcp/chart.py b/src/excel_mcp/chart.py
index 20b4c66..e92fd6f 100644
--- a/src/excel_mcp/chart.py
+++ b/src/excel_mcp/chart.py
@@ -66,6 +66,12 @@ def create_chart_in_sheet(
     style: Optional[Dict] = None
 ) -> dict[str, Any]:
     """Create chart in sheet with enhanced styling options"""
+    # Ensure style dict exists and defaults to showing data labels
+    if style is None:
+        style = {"show_data_labels": True}
+    else:
+        # If caller omitted the flag, default to True
+        style.setdefault("show_data_labels", True)
     try:
         wb = load_workbook(filepath)
         if sheet_name not in wb.sheetnames:
@@ -165,22 +171,36 @@ def create_chart_in_sheet(
 
         # Apply style if provided
         try:
-            if style:
-                if style.get("show_legend", True):
-                    chart.legend = Legend()
-                    chart.legend.position = style.get("legend_position", "r")
-                else:
-                    chart.legend = None
+            if style.get("show_legend", True):
+                chart.legend = Legend()
+                chart.legend.position = style.get("legend_position", "r")
+            else:
+                chart.legend = None
 
-                if style.get("show_data_labels", False):
-                    chart.dataLabels = DataLabelList()
-                    chart.dataLabels.showVal = True
+            if style.get("show_data_labels", False):
+                data_labels = DataLabelList()
+                # Gather optional overrides
+                dlo = style.get("data_label_options", {}) if isinstance(style.get("data_label_options", {}), dict) else {}
 
-                if style.get("grid_lines", False):
-                    if hasattr(chart, "x_axis"):
-                        chart.x_axis.majorGridlines = ChartLines()
-                    if hasattr(chart, "y_axis"):
-                        chart.y_axis.majorGridlines = ChartLines()
+                # Helper to read bool with fallback
+                def _opt(name: str, default: bool) -> bool:
+                    return bool(dlo.get(name, default))
+
+                # Apply options – Excel will concatenate any that are set to True
+                data_labels.showVal = _opt("show_val", True)
+                data_labels.showCatName = _opt("show_cat_name", False)
+                data_labels.showSerName = _opt("show_ser_name", False)
+                data_labels.showLegendKey = _opt("show_legend_key", False)
+                data_labels.showPercent = _opt("show_percent", False)
+                data_labels.showBubbleSize = _opt("show_bubble_size", False)
+
+                chart.dataLabels = data_labels
+
+            if style.get("grid_lines", False):
+                if hasattr(chart, "x_axis"):
+                    chart.x_axis.majorGridlines = ChartLines()
+                if hasattr(chart, "y_axis"):
+                    chart.y_axis.majorGridlines = ChartLines()
         except Exception as e:
             logger.error(f"Failed to apply chart style: {e}")
             raise ChartError(f"Failed to apply chart style: {str(e)}")